# 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 141
1. ## statistics

The data set given below has y^ = 3x - 5 for its regression equation. Find the standard error of estimate. x 3 2 5 8 y 4 1 10 19 A) 1.29 B) 0 C) 2.06 D) 0.17

asked by ericka on March 23, 2012
2. ## Algebra

Find an equation of the line having the given slope and containing the given point. Express your answer in the form x=a,y=b or y=mx+b; with m=-8,(7,0)? how do I do this?

asked by A.W. on March 2, 2009
3. ## Math

I need some guidance on this next problem. Slope intercept form of the equation of the line described. Through (2,3) perpendicular to y=5

asked by Hannah on January 7, 2014
4. ## Pre-Calculus

Write an equation in slope-intercept form of the line with the given parametric equations. x=t+6 y=2t-4

asked by Alexis on March 3, 2014
5. ## Ms. Sue Math Help Please

Which equation matches the statement "The product of 3 and the difference of a number and 10 is 15" Answer choices: 3 + (x - 10) = 15 3x - 10 = 15 3 (x - 10) = 15 3 x/10 = 15

asked by Katalina on January 8, 2014
6. ## Math

For the data in the table, does y vary directly with x? If it does, write an equation for the direct variation. X 52 = 32 = 20 = 8 Y 39 = 24 = 15 = 6

asked by Katie on January 8, 2014
7. ## math

do i use the quadratic equation when solving this problem. 3x^2-5x-7=0. If so the answer that i get is (5+-square root of 59)/ 6 is this correct

asked by jen on April 6, 2010
8. ## algebra

• Post your 50-word response to the following: If you are looking at a graph of a quadratic equation, how do you determine where the solutions are?

asked by Anonymous on February 6, 2010
9. ## Math

How do you write a quadratic equation with information saying that it opens upward, has a pattern of 1, 3, 5, and a vertex of (-4,5)?

asked by Anonymous on January 18, 2015
10. ## Ellipses Part 2:)

4x^2+y^2-48x-4y+48=0 what is the distance from c to foci of this equation The center is (6,2) major is 10 i think and minor is 5 but they might be wrong

asked by Honey on May 11, 2012
11. ## maths (2nd time)

Solve the equation. Round to the nearest hundredth: 1. 1.59x+4.23=3.56x+2.12 2. -3(1.25-2.48x)=8.15+5.86

asked by grace on September 20, 2009
12. ## Trigonometry

Is the given equation an identity or a conditional eqution sin(-x) tan(-x) + cos(-x) = sec x

asked by Evan on October 1, 2016
13. ## calculus

Find an equation of the tangent to the curve at the point corresponding to the given value of the parameter. x=tcos(t), y=tsin(t); t=π

asked by alex on May 4, 2017
14. ## College algebra

I need help finding an equation of the line containg (-5,-9)and (-2,-7) the answer has to be in slope-intercept form y=? Can anyone please help me with this?

asked by muff on November 28, 2009
15. ## math

if my example is a y=kx one and y=-5 and x=10 which are directly proportional why can't I just isolate the "k" (constant) and solve as a regular algebraic equation?

asked by Nicole on January 28, 2012
16. ## math

write the algebraic equation for "after 7 is added to a number, the sum is divided by 4 and the result is 12"

asked by ji on May 14, 2013
17. ## maths:

Solve the equation. Round to the nearest hundredth: 1. 1.59x+4.23=3.56x+2.12 2. -3(1.25-2.48x)=8.15+5.86

asked by grace on September 20, 2009
18. ## Analytic Geometry

Simplify the given equation and graph x^2-xy+y^2-3=0 (please answer. Needed for my studies tonight. Thanks!) PS: i will really appreciate your response. :)

asked by Earis on May 3, 2016
19. ## 7th grade honors math

Which equation represents an inverse variation? A.3x=2y B.2-2x+y=0 C.y squared= x D.xy=5 If you could tell me the anser then explain how you got it that would be awesome!

asked by Nora on March 14, 2011
20. ## math

The numbers -3, -4, and 6 are used once and substitued at random for a, b, and c in the equation ax+b=c. What is the probability that x turns out to be negative. I'm not sure where to begin with this. Can you help?

asked by Phillip on February 25, 2010
21. ## geochemistry

Been trying to balance this equation for a while, but can't get the right answer. any help would be apperciated! CH2O (aq) + NO3 - ---> N2 + HCO3 - + CO2(g)

asked by jason on March 14, 2013

Given that the cubic equation has rational coefficients and has the root , determine the values of a and b. I got a=2 and b=4. But the answer is a=-6 and b=-20

asked by Anonymous on October 4, 2016
23. ## Geometry

Find the equation of a circle centre on the line y=2x+1 touching the y axis and passing through A(4,5)

asked by Shanu on January 22, 2015
24. ## Math

Directions: Find all solutions of the equation in the interval (0, 2pi) sin x/2=1-cosx

asked by Lola on February 3, 2015
25. ## calculus

x = sin(θ/2), y= cos(θ/2), −π ≤ θ ≤ π. Eliminate the parameter to find a Cartesian equation of the curve.

asked by alex on May 4, 2017
26. ## Maths

Number of solutions satisfying the equation, 3x²-2x³=log(x²+1)-logx is a) 1 b) 2 c) 3 d) none

asked by Muffin on October 19, 2016
27. ## CHEMISTRY

what volume of hydrogen is produced with excess HCL according to the equation Zn+2HCL-ZnCL2+H2

asked by FEMI on December 10, 2016
28. ## College Algebra

The line through (2, 5), perpendicular to y = -7/3x-1 Question: Write an equation in slope intercept form.

asked by Morpheous on September 13, 2017
29. ## Math

sorry I wrote problem wrong: Which equation would you use to find out if the two lines in the graph are parallel:(a)(1,4) and (-1,1) (b) (3,3) and (-1,-1) a. 4-1/-2-1 = 3-1/3-1 b. 4-1/-2-1 = 3-(-1)/3-1 c. 4-1/1-(-2)= 3-(-1)/3-(-1) d. 1-(-2)/4-1 = 3-1/3-1

asked by BUBBLES on February 3, 2015
30. ## math

Find the equation of the line tangent to the curve 2(x^2+y^2)^2=25(x^2+y^2) at a point (3,-1) written in the form y = mx+b

asked by Judith on October 2, 2016
31. ## Algebra

Find the equation of the line through the given pair of points in standard form using only integers. 3) (5, 2) and (-1, 6)

asked by Michael on September 14, 2017
32. ## trig

Write the following equation in standard form and identify the type of conic: 9y^2 - 4x^2 + 8x + 18y + 41 = 0

asked by James on June 14, 2010
33. ## Equation

Write an equation that satisfies the conditions stated in Exercises Parallel to the line y=-4x + 1

asked by Lisa D on June 23, 2010
34. ## critical maths problem need help!!!

show that any fuction y(t)=acosx+bsinx ,satisfied the differential equation y^"+wy=0 and also find the value of (a) and (b)

asked by edward on August 23, 2015
35. ## Trig

find the equation for the cosine function that has an amplitude of 3/5, a period of 3pi/2 and a y-intercept of 5.

asked by Jon on May 3, 2016
36. ## Math

Solve the following equation in the complex number system. Please show all of your work. x^4 – 13x^2 – 90 = 0

asked by Greg - PV on June 9, 2011
37. ## algebra

Write an equation of a line that passes through the points (-6,7) and has a slope of -4 How do I do this? it would be y equals -4x but not sure how to do the rest.

asked by Elisa on September 26, 2009
38. ## Pre Calculus

use a calculator to find approximate solutions of the equation. 8.06x^2+25.8726x-25.047256=0

asked by Carol on September 27, 2009
39. ## Chemistry

Please check if I've balance the equation correctly. C8H18 + 25/2O2 --> 8CO2 + 9H2O

asked by Sarah on September 29, 2010
40. ## algebra

what is the equation of a parabola whose vertex is (6,0) and whose graph is half as tall as y=x^2 and opens upside down

asked by bob on August 23, 2014
41. ## AP Chemistry

What is the chemical equation that corresponds to the standard molar enthalpy of formation of N2O?

asked by jules on February 9, 2011
42. ## Direct Variations

Suppose y varies directly with x. Write a direct variation equation that relates x and y. y=10.4 when x=4 y=3.4x* y=3.8x y=3.2x y=2.6x

asked by Person on November 15, 2017

The equation Ax^2 + 4y^2 = 16 represents an ellipse. Find all values of A such that its intersection with y = |x| has coordinates (x,y) which are integers.

asked by Andy on December 19, 2010
44. ## Precalculus(URGENT)

determoine whether the equation defines y as a function of x y= the square root of(-3x-6) please please show work

asked by Arielt -Help now fast due tommorow on April 1, 2010
45. ## Calculus

Find an equation of the tangent line to the graph of f(x)=xsinx when x=0. A. y=0 B. f'(x)=0 C. y=xcosx+sinx D. y=x E. None of these

asked by Anonymous on November 30, 2014
46. ## MATH

for the data in the table does y vary directly with x if it does write an equation for the direct variation x y 4 28 6 48 8 72 yes;y=2x yes;y=5x** yes;y=7x no

asked by School Rocks on December 19, 2017
47. ## chemistry

Write the 12 mole ratios that can be derived from the equation for the combustion of isopropyl alcohol?

asked by stephanie on December 8, 2010
48. ## Math

Find the equation of the parabola whose axis of symmetry is horizontal and passes through the points (1, 2), (3, -2) and (7, -6).

asked by amikhailov on July 7, 2016
49. ## Algebra

Suppose y varies directly with x. Write a direct variation equation that relates x and y. y= 7 1/2 when x=3 y=3/2x y=2/3x* y=5/2x y=2/5x

asked by Person on November 15, 2017
50. ## maths

find the equation of the tangent to the curve 3xy^2 -4+2y=29 at the point (1,3)using implicit differentiation.

asked by maria on June 14, 2017
51. ## Chemistry

Solve for the missing compound in the balanced equation: 3PbO + X ----> 3Pb + N2 + 3H2O please help .

asked by Jazmine on February 17, 2011
52. ## Math

Write an equation in the form y=mx+b to represents the height of the water , x, after adding the marbles , y.

asked by Jil on November 16, 2017
53. ## Trig

Solve the equation on the interval 0 less than or equal 0 < 2pi. 1. sec 30/2 = -2 2. cos(20 - pi/2) = -1 3. tan(0/2 + pi/3) = 1

asked by KC on September 25, 2007
54. ## Math

Change the following to the standard equation of the ellipse 1. 5x^2 + 3y^2 = 15 2. x^2 + 12y^2 = 16 3. 3y^2 + 4x^2 = 3 And please can you give the value of a, b and c of this equations... so that I can sketch it....

asked by Tsunayoshi on August 25, 2014
55. ## math

write an.algebraic equation for autumn has,1 brother. this is 3 less than the number of brothers chase has,b

asked by jenny on October 9, 2012
56. ## math

Use a graphing utility to approximate the solutions (to three decimal places) of the given equation in the interval (-pi/2, pi/2) a. 1 b. –1 c. 1/2 d. 2 e. 0

asked by megan on July 11, 2016
57. ## Algebra

asked by TryToForgetLove on September 29, 2011
58. ## algebra 2

Write an equation in standard form for the hyperbola with center (0,0), vertex(4,0) , and focus (8,0).

asked by sam on April 26, 2012
59. ## Chemistry

What are the coefficent balance of this chemical equation H2SO4+NaNO2---->NHO2+Na2SO4?

asked by Jarred on August 5, 2010
60. ## Calculus

Hello! I am a little stuck (probably because I cannot remember my trigonometric functions). Does anyone know how to solve this equation? [-sin(x)]^2-2cosx

asked by Joe Schmo on December 12, 2010
61. ## physics

Write down the unit in which reaction rate is measured in this observation? Equation is Zn(s)+I~ZnI

asked by Refilwe on August 24, 2014
62. ## Biology

Could anyone suggest a web site where i could get the structual formulae and the equation for the hydrolosis of lactose thanks

asked by Bex on March 22, 2007
63. ## Pre calculus

Use the given conditions to write an equation for the line in point-slope form. Passing through (-5, -7) and (-8, -6)

64. ## Chemistry

What volume in dm³ of KCl is obtained in the following equation 2KClO3-----> 2KCl + 3O2?

asked by Summit on November 8, 2016
65. ## Algebra

Using the Gauss-Jordan method need to determine the coefficients a,b,c of the quadratic equation x=ax squared +bx+c y=5.4 and x=8

asked by mike on December 13, 2009
66. ## Pre-calculus

Plss... help me.. what is the equation of parabola with vertex on the line y=x, axis parallel to Ox, and passing through (6,-2) and (3,4)? thanks!

asked by Ace on August 25, 2016
67. ## Calculus

Find the equation of the tangent line to the graph of the function f(x)= 2x^3−3x^2+4x+2 at x=2 I got y=16x-12 but I know it is wrong.

asked by Anonymous on October 15, 2012
68. ## Geometry

Find the equation of a line in slope-intercept form whose parametric equations are x=2t+3 and y=4t-1.

asked by Lenora on December 10, 2009
69. ## chemistry

Write the equation for the decomposition of water into its elements. Phase symbols are not graded.

asked by lee on April 17, 2013
70. ## math

35. If b is postive integers less than 400 and more than 100, then how many integer pairs (a,b) satisify the equation a/b=2/9?

asked by vincent on August 21, 2014
71. ## geometry

Find the equation of a line in slope-intercept form whose parametric equations are x = 2t + 3 and y = 4t - 1

asked by Lenora on December 10, 2009
72. ## math

What are the coordinates of the center of the circle and the length of the radius with the equation (x+3)^2+(y-2)^2=16? Show your work.

asked by kk on May 2, 2013
73. ## Pre-Calculus

Write a linear equation to fit the description. The line with a slope of zero containing the y-intercept of x/3 + y/9 = 1 I'm not sure what to do here. Can someone please help me?

asked by Yani on September 3, 2015
74. ## jccc

when applying the equation of kinematics for an object moving in one dimension which of the following statements is true

asked by amy on September 2, 2016
75. ## math

Write equation and solve. Hell eleven less than five times a number is19

asked by Micaela on October 16, 2012
76. ## chemistry

Using the balanced equation, Mg + 2HCl= H2 + MgCl2, calculate the amount of MG need to react with 25 mL of 6 M HCl.

asked by Jamey on October 18, 2011
77. ## chemistry

what is the net ionic equation for Na3PO4 + ZnSO4=Zn3(PO4)2+ Na2SO4

asked by Jed on September 27, 2010
78. ## Maths

Solve the equation: Give your answer as a fraction in its lowest terms: 2x-5=7-6x I'm getting -1/3 but i think that's wrong!?! Would appreciate some help please thanks! M

asked by Marian on February 9, 2011
79. ## math

use each of the digits 1, 2, 3 (one time each)and any combination of operations to create and equation where the answer is 5 please help Abbigail

asked by Abbigail on November 28, 2012
80. ## Math

write the equation of the hyperbola in graphing form from the given information: Vertices at (2,0) and (-2,0); foci at (3,0) and (-3,0)

asked by Anonymous on June 14, 2017
81. ## math

35. If b is positive integers less than 400 and more than 100, then how many integer pairs (a,b) satisfy the equation a/b=2/9?

asked by vincent on August 22, 2014
82. ## Pre-Calculus

Find the inverse of the following quadratic equation. Hint: Complete the square first. y= x²+14x+50

asked by AwesomeGuy on March 7, 2013
83. ## Math

Write the equation of a line that passes through (-10,3) and (-2,-5). What I have: y= -3/13x +b After doing y2 - y1/x2 - x, I got a slope of -3/13, but I'm confused on how to get the y intercept.

asked by Anonymous on August 27, 2016
84. ## chemistry

Write an equation for the hydrolysis of each of the following salt: i) NaCH2H3O2; ii) Na2CO3; iii) NH4Br

asked by chris on October 13, 2011
85. ## algebra 2

Write an equation in standard form for the hyperbola with center (0,0), vertex(4,0) , and focus (8,0). 1) x^2/64-x^2/16=1 2)x^2/16-y^2/64=1 3)y^2/48-x^2/16=1 4)x^2/16-y^2/48=1

asked by sam on April 27, 2012
86. ## Gas Stoichiometry

What mass of ammonia is produced when 3.08 L of nitrogen (at STP) react completely in the following equation?

asked by Jenny on May 6, 2013
87. ## Math

1. Suppose y varies directly with x. Write a direct variation equation that relates x and y. y= 7 1/2 when x=3 a. y= 3/2 x b. y= 2/3 x c. y= 5/2 x d. y= 2/5 x 2. Suppose y varies directly with x. Write a direct variation equation that relates x and y.

asked by Kaai97 on December 3, 2015
88. ## Engineering Math

solve the 1st differential equation: y1+4y=cos(x) with intial condition y(pie/3)=1

asked by Thomas on June 24, 2011
89. ## math

find the equation, in function form, of athe line that passes through the points(1/2,-3) and (7/6,5/9)

asked by sam on November 19, 2012
90. ## Maths

Solve the equation, give your answer as a fraction in its lowest terms: x-2= 4x+7/6 (the whole part 4x+7 is over the 6) I'm getting -6 !!

asked by Marian on February 9, 2011
91. ## College Math

What is conditional, and identity or a contradiction ? in terms of a linear equation. Please can you give some examples

asked by HM on September 29, 2011
92. ## Math check

Find an equation of the line having the given slope and contaning the given point. m=-3(6,7) I got y=-3x-25 for the answear. Is this correct?

asked by Bryan on December 11, 2008
93. ## Chemistry

Write the net ionic equation for HClO4(aq) + NaOH(aq) --> H2O (l) + NaClO4(aq).

asked by Heidy on August 15, 2016
94. ## Tangent Lines (2)-Calculus

find an equation of the line tangent to y= sqrt(25-x^2) at the point (3,4) i got y= x/8 + 29/8 this is wrong. but im not sure why. can you explain thank you

asked by Greg on March 20, 2013
95. ## Algebra

In the equation x^2 + mx + n = 0, m and n are integers. The only possible value for x is -3. What is the value of m? If I substitute -3 and solve for m, I can get many values for m based on what I pick for n. How can the answer only be 6?

asked by Anthony on August 31, 2014
96. ## science

derive second equation of motion.S=ut+1/2at2 graphycally where the symbols have their usual meanings.

asked by rajashri on August 31, 2014
97. ## Algebra 2 ..........

When finding an equation of a sine and cosine graph can I use any of the three coordinates (that have the same y value ) to substitute for h and k? Is there a designated one?

asked by Anonymous on May 5, 2013
98. ## ChEmIsTrY

the equlibrium equation is (I2)^2(CO2)^5/(CO)^5. If the (CO) starts at 1.0 M and decreases to 0.25 M at equilibrium, give the value of Keq. How would i do that??

asked by Miley on May 12, 2008
99. ## Pre-Algebra

I don't understand this equation: Given f(x)=4(x)+1 find the value. f(3) It's fairly basic, you just plug 3 in for x, so it would be 4(3)+1 and then you'd just simplify it :)

asked by Kayla on April 19, 2007
100. ## chemistry

3CaCl2+2Na3PO4 -----------> 1Ca3(PO4)2+6NaCl Did I correctly balance this equation?

asked by Wurola on April 23, 2012