# why does the equation x^2=-9 has no real solution why does the equation x^2 = 9 has two solutions

56,329 questions, page 219
1. ## Math

Suppose the equation v=16.2x^2 - 192.1x + 2800 represents the value of a house from 1925 to 1950. When did the house have the lowest value? Round to the nearest whole number. (X=0 in 1925)

asked by Koki on May 4, 2016
2. ## Algebra 2

Standard form for both equation with steps 16x^2-96x+144+25y^2=400 16x^2+192x+576+25y^2=1600

asked by Spence on August 23, 2015
3. ## Pre-Calculus/Calculus

I am too embarassed to ask this Calculus (really pre-calculus) question in tutoring, because I know I should know. Is the inverse of f(x)=3x-1 actually f(x)=1/3x+1? How do I find it? What if it asks the same equation replaced with f to the -1 power (x)? I

asked by Molly on July 1, 2008
4. ## Algebra

equations and inequalities unit test for questions 1-5, solve the equation 4. 3(4-2x)=-2x (1 point) a. -1*** b. 1 c. 2 d. 3 5. 5.4+0.2x=-1.4x+8.6 a. 2 b. -2 c. .2*** d. 20 For questions 6-7, simplify the expression 6. -4 - 5(x+8) a.-5x - 44 b.-5x + 36***

asked by conchobar (connor) on February 1, 2016
5. ## Precalc

An ellipse has this Cartesian equation: ((x-2)/5)^2 + ((y-4)/3)^2 = 1 Find the focal radius Find the eccentricity Write the parametric equations for the ellipse Transform into the form, Ax^2 + By^2 + Cx + Dy + E = 0

asked by Grace on January 20, 2012
6. ## Physics/Math

Given two vectors, a and b, such that a + b = a - b, find the magnitude of b. Consider the equation a + b = a - b to be n vector notation and both a and b have components. Subtract the a vector from both sides. You are left with b = -b That can only be

asked by COFFEE on February 18, 2007
7. ## Algebra

Compare the line passing through the points (−3, −11) and (6, 4) to the line given by the equation y=35x−6. A. They have the same slope. B. They have the same x-intercept. C. The two lines are perpendicular. D. They have the same y-intercept. I say c

asked by Kaashif on April 24, 2016
8. ## chemistry 1

When butane undergoes complete combustion , the products are CO2 and H2O C4H10(g) + O2(g)-> CO2(g) + H2O(g) What is the value of the coefficient for oxygen when this equation is balanced

asked by jeanette on March 7, 2010
9. ## Chemistry

What is the wavelength in Angstroms of radiation that has a frequency of 4.00 x 10^14 s-1? I tried the equation wavelength= constant / frequency. And the fact that 1 Angstrom = 1x 10^-10 m, but I don't see how the correct answer turns out to be 7.5 x 10^3

asked by Sarah on November 14, 2012
10. ## Honors Pre-Cal

We're reviewing and I forgot how to do this. Given y=x2-4+3 (x2 is x squared) a)write in standard from b)find vertex c)find equation of the axis of symmetry d)find the x-intercepts e)find the y-intercept

asked by Helen on October 10, 2010
11. ## Chemistry

Zinc replaces Hydrogen in hydrochloric acid. Write the equation and identify how many grams of this acid is required to produce 10^24 atoms of hydrogen.

asked by Jay on June 5, 2018
12. ## math

The blue line of best fit for boys intersects the vertical axis at 20 inches and the point (12.5, 25). Which equation best describes the boy's line of best fit?

asked by Sam on February 1, 2014

Find the equation of the tangent line to the graph of f(x) = 2x − 6/x + 1 at the point at which x = 0. (Let x be the independent variable and y be the dependent variable.) I don't know how to find the derivative, i Keep getting it wrong. But I know where

asked by Angelica on October 1, 2015
14. ## math

A car company charges \$35 per day plus 20 cents per mile to rent a car. Write an equation to express the average cost per x mile.

asked by lisa on January 24, 2014
15. ## Pre algebra

The width of a triangle is x-3 and the length is 2x-1. Write and solve an equation to find the perimeter and area of the rectangle if the measures of its length and width are in a 1:3 proportion

asked by Ashley on May 25, 2011
16. ## Physics

Velocity V of a streched string depends on tension T and mass per unit length M of the string. Create an equation for velocity V using dimensional analysis?

asked by Physics_looser on August 15, 2017
17. ## Algebra word problem

Mary is two years older than Robert. The sum of their ages is 28. Write an expression for each person, write the equation for the situation and find out how old each person is.

asked by Lee Ann on November 30, 2014
18. ## Algebra HELP

h(x)= 3x^(5) + 2x^(4) + 15x^(3) + 10x^(2) - 528x - 352 for this equation how would I know to use the square root of 11 in synthetic division to be a factor? I used the p / q list but I did not get sqt root of 11 as a possible factor. could someone help

asked by Amy on November 17, 2010
19. ## physics

A wave traveling along the x axis is described mathematically by the equation y = 0.15 sin (7.5πt - 0.49πx), where y is the displacement (in meters), t is in seconds, and x is in meters. What is the speed of the wave?

asked by Marco on December 3, 2011
20. ## Calculus

The equation of motion of a particle is s = t3 − 12t, where s is in meters and t is in seconds. For the velocity function, I got v(t)=3t^2-12 and for acceleration, a(t)=6t. The final question is: Find the acceleration when the velocity is 0. How do I do

asked by Kelly on September 29, 2015
21. ## Algebra

how do you write a polynomial equation that represents the cost of renting a car for m miles.The cost to rent a car for a day is \$15 plus \$0.15 for each mile driven. help please!!!!

asked by chelsea on December 1, 2011
22. ## Math

Write the equation of a line in slope intercept form that is parallel to the line y= 1/3x+ 5 and passes through (-9, 5). Do not use any spaces. Slope should be a reduced improper fraction.

asked by Natalie on May 25, 2012
23. ## linear approx

I have no idea how to do this, anyone have any hints? Use linear approximation, i.e. the tangent line, to approximate as follows: cubed root 63.6 The equation of the tangent line to at f(x) x=64 can be written in the form y= thanks

asked by emily on March 28, 2007
24. ## Chemistry

The rusting of iron is represented by the equation 4Fe+3O2=2Fe2O. A 1.45-mol sample of iron, how many moles of Fe2O3 will there be after rusting has completed.

asked by keisha on November 23, 2014
25. ## Math

An elevator has a maximum lift of 2,000 lb. You are moving 55-lb boxes of books. Write an equation and estimate how many boxes you can safely place on the elevator.

asked by Anonymous ❕ on November 26, 2018
26. ## math

alexander had some nickles in his bank. he added 3 dimes to the bank and then he had 85 cents.how many nickles did he have left? write an equation and work backward to solve.

asked by hanna on November 6, 2007
27. ## Organic Chemistry

Benzene is often produced as a by-product during the synthesis of phenylmagnesium bromide. how can its formation be explained? Write a balanced chemical equation for the formation of benzene.

asked by Blair on February 27, 2009
28. ## Chemistry

here is the equation:Zn(s)+2HCl(aq)-->ZnCl2(aq)+H2(aq).If 20.0 moles of zinc react with excess hydrochloric acid. how many moles of zinc chloride are produced?....thxxx

asked by Pierrysen on May 28, 2010
29. ## In need of algebra help!

You are making a rectangular table. The area of the table should be 10 ft^2. You want the length of the table to be 1 ft shorter than twice its width. What should the dimensions of the table be? Okay, so, I'm not sure how to put this into an equation. The

asked by Heidi on March 30, 2015
30. ## Algebra

A rectangle's width is 6 inches less than its length. If it's area is 216 square inches find the dimensions of the rectangle. Write an equation and solve

asked by Kevin on March 28, 2017
31. ## math - geometry

Austin wants to sketch the graph of a circle represented by the given equation. (x - 4)2 + (y + 7)2 = 64 Using complete sentences, describe the steps used to sketch the circle on a coordinate grid

asked by kris on August 19, 2013
32. ## Algebra 1

For the data in the table, does y vary directly with x? If it does choose an equation for the direct variation. x|y 8|11 16|22 24|33 a. yes; y=2.75x b. yes; y=0.6875x c. yes; y= 1.375x d. no; y does not vary directly with x i think its d, but i'm not sure.

33. ## math

The equation d =70t represents the distance in miles covered after traveling at 70 miles per hour for t hours. How can i make this a table for every half hour?

asked by my name on April 21, 2008
34. ## physics

A wave traveling along the x axis is described mathematically by the equation y = 0.17sin(8.5πt + 0.45πx), where y is the displacement (in meters), t is in seconds, and x is in meters. What is the speed of the wave?

asked by Amelia on January 27, 2018
35. ## math

An arch is in the form of a semi-ellipse, with its major axis as the span. If the span is 80 feet and the height is 30 feet write the standard equation.

asked by brandon on March 24, 2010

1)Determine the equation of the polynomial function of degree 3, with zeros -2, -1, and 4. The graph of this function passes through (5, -84). I have no idea how to do this one. 2) When 4x^4 - a5x^2 + px + 6 is divided by 2x+1, the remainder is 2.

asked by Alex on January 20, 2008
37. ## Math

A=1/2H(B+b) Solve for H Let's start by getting rid of the fraction. Multiply both sides by 2 (whatever operation you do to one side of an equation you must do to the other side as well): 2(A) = 2[1/2H(B+b)] 2A = H(B+b) Now divide both sides by (B+b) and

asked by Joseph on January 17, 2007
38. ## GRADE 12 PHYSICS AGAIN

it has been 2 hours, can't someone please help me? I need to know if what I did was right, I think it is wrong and one of the numbers is supposed to subtracted instead of added. 2.44(t+1)^2 = 2.44 (t^2-2t-1) d=2.44t^2-4.88t+2.44 & then

asked by Haley on September 12, 2007
39. ## Math Movers

Movers A mover charges \$500 for the first 100 miles plus \$10 for each additional mile. If C represents the charge and M represents miles. What would the equation look like for this question?

asked by John on March 29, 2013
40. ## math check answer plz

you earn \$7.50 per hr to help ur uncle in his shop. you earn \$33.75 . write and solve an equation to find how may hrs u worked. I put \$7.50 x hours= \$33.75 and hours is 4.5 is that correct?

asked by scooby on September 8, 2013
41. ## Economics

If I'm graphing a PAE equation to determine the output gap and what type, say my Y is less than Y*. Am I correct in thinking the output gap will be a negative number, which would contractionary?

asked by Jay on November 15, 2007
42. ## Math

One angle of a triangle measures 120 degrees. The other two angles are congruent. Write and solve an equation to find the measure of the congruent angles.

asked by Mike on February 13, 2012
43. ## math

The sales tax on an item costing \$236 is \$28.20. What is the sales tax rate to nearest tenth? Write ratio equation and solve it!

asked by Carah on September 10, 2009
44. ## math

The blue line of best fit for boys intersects the vertical axis at 55 centimeters and the point (12.5, 70). What equation best describes the boy's line of best fit?

asked by notsayingname on October 25, 2016
45. ## algebra

I want to visit a friend that lives 200 miles away. Gas is \$4 a gallon. My car gets 50 miles every 2 gallons of gas. How can I solve this using an literal equation?

asked by mary on January 9, 2017
46. ## Can someone check this

A salesperson earns \$200 a week plus a 4% commission on her sales. Which equation models the relationship between her sales in a given week, s, and her weekly earnings, e? Is it e=200s+4?

asked by Priscilla on November 5, 2015
47. ## Math hellppp

the balance listed on kims bank statement was \$65 in April. in may, her balance was \$-12. what equation represents the difference in her account balances from April to may? A. 65-12=53 B. 65 - (-12)=77 (MY ANSWER) C. -65-(-12)= - 53 D. -65+-12 = -77

asked by Hayley on August 16, 2017
48. ## Math

Jake earns \$11.50 each time he mows the lawn for his parents. He has earned \$69. Use the equation below to find the number of times he has mowed the lawn (m) for his parents. 69 = 11.5m

asked by Barry Vacker on February 12, 2019
49. ## Chemistry

Calculate the energy released when an electron is added to a hydrogen nucleus. Assume the transition is n= infinite to n=1. I know equation to use but how do I calculate when n is infinite and no number ?? Please some help

asked by Anonymous on November 29, 2012
50. ## chemistry

For the balanced equation shown below, how many moles of C4H10O reacted, if 0.5599 moles of H2O are produced? C4H10O+6O2 --> 4CO2+5H2O

asked by SUPAMAN on December 15, 2011
51. ## math

An arch is in the form of a semi-ellipse, with its major axis as the span. If the span is 80 feet and the height is 30 feet write the standard equation.

asked by dcw on March 23, 2010
52. ## Math

Hello I am mother trying to explain to my 13 year-old daughter the result of this equation: 7x^2+7y-4x^2-4y equals to 3x^2-3y I just want to know that I am right since my daughter insists that that was not what the teacher had on the board she got 34y

asked by Anonymous on September 10, 2015
53. ## Math

Ricardo spent \$37 for a jacket which included \$2.38 in sales tax. Write and solve an addition equation to find the price of the jacket before tax

asked by Luna on January 13, 2016
54. ## College Algebra

Find the equation of the parabola y = ax2 + bx + c that passes through the points. To verify your result, use a graphing utility to plot the points and graph the parabola. (−2, −15), (−1, −4), (1/2,-10) y=?

asked by Jack on July 21, 2013
55. ## chemistry

enzymes convert glucose M=180.2 to ethanol M=46.1 according to the equation C6H12O6=2C2H5OH + 2CO2 what is the maximum mass of ethanol that can be made from 15.5 kg of glucose?

asked by JENNA on May 4, 2013
56. ## chemistry

What volume of 0.714 M K3PO4 is required to react with 27 mL of 0.97 M MgCl2 according to the equation 2 K3PO4 + 3 MgCl2 → Mg3(PO4)2 + 6 KCl Answer in units of mL

asked by Anonymous on October 28, 2013
57. ## Acc

A crane with the mass of 500kg,lifting an object of the mass of 50kg, what wil be the gravitational potential energy of a crane?. I need the equation and the answear.

asked by Thapelo on February 24, 2011
58. ## Algebra2

write an equation to represent the situation: if a player made 12 out of 15 free throws, how many consecutive free throws would she have to make to raise the percent to 85%.

asked by Joleen on December 27, 2016
59. ## trig

how do you find algebraically the measure of the obtuse angle, to the nearest degree, that satisfies the equation 3 sec theta = 5 is it sec theta = 5/3 and then cos -1 (5/8) = 0.4

asked by Anonymous on June 11, 2014
60. ## Math

George can spend \$34.80 for his dinner. He wants to tip the waiter 20% of the cost of his meal. How much money does he spend on the tip? Translate the question into an equation. Do not solve.

asked by Gerald on October 7, 2007
61. ## Math

Simplify: f(x)=sqrt (16-x^4)/ sinx This is to evaluate a limit, but I don't know if I can simplify the above equation. Because I tried to get rid of the radical in the numerator but I ended up with a radical in the denominator. >< Help

asked by Neee on August 14, 2010
62. ## algebra

A ball has been hit with an initial velocity of 24.5 m/sec from a height of 5.375 meters off the ground. Write an equation that models the height of the ball.

asked by Holly on January 5, 2011

A football is kicked with a speed of 18 m/s at an angle of 65° to the horizontal. How long is the football in the air? Neglect air resistance Would I use the equation y=y0 + voy t -1/2gt^2 ?

asked by Hannah on May 25, 2012
64. ## math

Line through (0,b) and (10,-5) is perpendicular to the line through (a,0) and (-6,-3). If all ordered pairs (a,b) which make the first sentence of this problem true are graphed, they all lie on a line. Find the equation of this line.

asked by Sam on September 17, 2014
65. ## Math

A cheese pizza costs \$5. Additional toppings cost \$1.50 each. Write and graph an equation in two variables that represents the total cost of a pizza.

asked by Sarah on February 29, 2016
66. ## Chemistry

Could you please tell me how to work out the net balanced equation of 'aqueous solutions of sodium sulfate and barium nitrate when they are mixed?' *Do we just ignore sulfate and nitrate???????

asked by Alloush on April 5, 2010
67. ## Physics

If a ball has a constant acceleration of 10m/s^2, how fast will the ball be rolling after 4 seconds? Would you multiply acceleration times time? So 10 x 4... or would you use the equation d=1/2gt^2?

asked by LK on May 29, 2010
68. ## Chemistry

What are the correct and accurate products of the following neutralization reaction. Then write the ionic form of the equation and the net ionic form. KOH + H2SO4 ->

asked by Emily on April 7, 2015
69. ## chemistry

Write the balanced equation and solubility product expression for the solubility equillibrium of Mn3(PO4)2: Ksp expression?

asked by Karly on November 29, 2010
70. ## Write in (x , y) Form

The letters r and theta represent polar coordinates. Write each equation in rectangular coordinates (x, y) form. (1) r = 4 (2) r = 3/(3 - cos(t)), where t = theta

asked by sharkman on February 23, 2008
71. ## pre-algebra

Solve the inequality- a/3>4 -2n 4 * 3 a>12 Do similar processes with the other inqualities. I hope this helps. Thanks for asking.

asked by Sarah on March 7, 2007
72. ## trig

A population of wolves in a country is represented by the equation P(t)= 80(0.98)^t, where t is the number of years since 1998. predict the number in the population in the year.

asked by lhencham on February 1, 2010
73. ## Chemistry

Given this equation. C3H8 + 5O2 -> CO2 + H2O. How many moles of O2 will be needed to comepletely burn 1.75 moles of propane C3H8?

asked by Pangilinan on August 30, 2014
74. ## math

Hi Dan, kindly provide detail equation how to arrived to your answer. 21 boys, 21 girls. 7:5 - 6 girsl is 21 boys to 15 girls [think -6]

asked by tante on November 20, 2015
75. ## Math - Quadratic Equations

The base of a triangle is 6 cm longer than its height. If the area of the triangle is 140cm^2, what is the length of the base? Im just confused on how the equation should be formed. Thanks.

asked by Anonymous on March 31, 2017
76. ## Chemistry

The balanced equation for the synthesis of water is: 2H2 + O2 > 2H2O If I have 5.5 grams of water, at least how many grams of Oxygen gas was needed?

asked by Erin on January 21, 2017
77. ## Math

As the candle burns,its length decreases at a rate of 2cm every 20minutes. Write down the equation to calculate the length of the candle

asked by Edward on January 22, 2017
78. ## calculus

Find the equation of a cubic function that gives you the surface area of the cans given a set volume. The set volume is 300ml

asked by Emily on October 17, 2010
79. ## college chemistry

if 2.00g of Zn is allowed to react with 2.00g of CuSO4 according to the equation CuSO4(aq) + Zn(s)-----> ZnSO4 (aq)+ Cu(s) how many grams of Zn will remain after the reaction is complete ?

asked by isabel on November 5, 2012
80. ## AP Chemistry

What are the two half-reactions for the basic oxidized-reduction reaction Fe(OH)2+ H2O2 --> Fe(OH)3? If I can find out the two half-reactions, I'll be able to balance the equation myself. Thanks!

asked by Sara on September 11, 2010
81. ## MATH PLZ HELP

well i'm stumped. i can't figure out how to solve this. solve for (x,y): 3/x + 2/y = 0 5/x - 1/y = 13 i can't graph it, and i can't use a calculator. i keep getting stuck on the second equation b/c i get 5y -13xy -x=0 and since 13 is a prime number i cant

asked by cody on September 21, 2011
82. ## algebra

A rectangular pool is 25 feet long and 12 feet wide. If the length is increased by 2x what is the new length? How would you use a quadratic equation to solve this?

asked by Mark on May 10, 2012
83. ## chemistry

How much heat is released when a mixture containing 12.6 g CS2 and 12.6 g Cl2 reacts by the following equation? CS2(g) + 3 Cl2(g) → S2Cl2(g) + CCl4(g) ΔH° = −230. kJ

asked by caroline on October 29, 2010
84. ## science

the basicity of tetraoxosulphate 6 acid is 2 explain the statement with an equation and show the reaction between tetraoxosulphate 6 acid with potassium hydroxide

asked by boss on April 30, 2019
85. ## Mathematics

if d sum of two numbers is 8 and their product is 15.if the answer of this equation is 3and5 find the number and check let the two numbers be xandy and you must check

asked by opeyemi on December 5, 2016
86. ## Math

Determine whether the equation defines y as a linear function of x. If so, write it in the form y = mx + b. Can someone please break this down to someone who's terrible in math. 6x-9y^2+8=0 a. y=6x+8 b. y=6/9x-8 c. y=6x-8 d. y=6/9x+8 e. y is not a linear

asked by Gregg on October 17, 2016
87. ## chemistry

How much heat is released when a mixture containing 12.6 g CS2 and 12.6 g Cl2 reacts by the following equation? CS2(g) + 3 Cl2(g) → S2Cl2(g) + CCl4(g) ΔH° = −230. kJ

asked by Emily on October 31, 2010
88. ## Algebra 2 Honors- Ellipses REAL ONE

for my homework problem i have the equation: (x^2/16) + (y^2/1) = 1 I need to find out the center, the vertices, co- vertices and the Foci. I have trouble knowing how to find them, so if you can please explain them. Thank you.

asked by Stephanie on April 30, 2008
89. ## math help asap

For the data in the table does y vary directly with x? if it does write an equation for the dorect variation. x;y 10,15 16,24 20,30 a:yes; y=1.5x b:yes;y=2x c:yes;y=x+5 d: y does not vary directly with x if you are from connections and know any other

asked by anon on February 22, 2017
90. ## Algebra 2 Honors- Ellipses

for my homework problem i have the equation: (x^2/16) + (y^2/4) = 1 I need to find out the center, the vertices, co- vertices and the Foci. I have trouble knowing how to find them, so if you can please explain them. Thank you.

asked by Stephanie on April 30, 2008
91. ## chemistry

complete and balance the following equation: CoCl*6H2O+ NH4Cl+ NH3+ H2O ---> [Co(NH3)5Cl]Cl2+ H2O

asked by anon on December 1, 2010
92. ## Physics

A wave on a string is described by the following equation (assume the +x direction is to the right). y = (18 cm) cos[ðx/(5.3 cm) - ð t/(14 s)] What is its period? What is its speed? In which direction does the wave travel? To the left or to the right?

asked by Anna on May 20, 2012
93. ## algebra

When I subsitute 5x+3 into the equation I get x=1/5 and y=2 is this correct? Try plugging in your final values for x and y into both of the original equations. If and only if the equations are true, then your answers are correct.

asked by Tony on March 20, 2007
94. ## math

an equation is being tested for symmetry with respect to the x-axis, the y-axis, and the origin. explain why, if two of these symmetries are present then remaining one must also be present.

asked by Anonymous on January 11, 2011
95. ## MATH

Can anyone please help me with this? Can anyone please build or generate at least five Pythagorean Triples using one of the many formulas available online. Then After building the triples, verify each of them in the Pythagorean Theorem equation. Thank you

asked by John on August 19, 2011
96. ## AP Chemistry

If you combine 2.00 ml 2.0 x 10^-3 M KSCN and 98.00 ml 2.0M Fe(NO3)3 what is the concentration of FeSCN? I know the equation (V concentrated*M concentrated)=(V diluted *M diluted) should be used, but how do you go about that when you have two initial

asked by Emily on March 12, 2008
97. ## math

Which of the following equations represents the equation for the line that is parallel to the given line and passes through the given point? y= 1/5 x - 10; (15, -16) A. y = -5x +19 B. y = 1/5x + 91/5 C. y = 1/5 x - 19 D. y = 5x - 19 I do know that to be

asked by Jane on April 11, 2012
98. ## Algebra

my question is:Suppose you want to add a sprinkler system, and the location of one section of the sprinkler system le can be described by the equation: y= -1/2x -4, this is what I got 4+y= -1/2x - 4 +4, 4y= 1/2x -1/2x; y=4 and x=0 making the answer (0,4).

asked by A. W. on February 15, 2009
99. ## algebra

well i'm stumped. i can't figure out how to solve this. solve for (x,y): 3/x + 2/y = 0 5/x - 1/y = 13 i can't graph it, and i can't use a calculator. i keep getting stuck on the second equation b/c i get 5y -13xy -x=0 and since 13 is a prime number i cant

asked by cody on September 21, 2011
100. ## Algebra function problem, check/help?

Set up a function for the following situation: The output of a function is 8 less than 3 times a number. B) Find the input when the output is 13? Would your equation look like: 8

asked by Allyson on October 19, 2010