# 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 489
1. ## Science // Chemistry

How many grams of KOH are needed to make 1.00L of a 1.3 molar (1.3 M) solution? ------------------ I am not sure how to start this question, my teacher wants us to use conversion factors and write it out but I don't get how I am supposed to start it.

asked by Anonymous on March 2, 2015
2. ## Math

Hi. So we had a long test with this question.. I was wondering how to solve it? Coz our teacher didn't discuss the answers.. and most probably we'll have the same type of question during midterms.. Find the Solution Set 9/|2-5x| - 4/y^2-3y = 5 2/|2-5x| +

asked by Jen on August 17, 2011
3. ## geometry

sodium has a body-centered cubic structure with a unit cell that is 430 picometers wide. estimate the radius of a sodium atom. please help me, I don't know how to get the solution. THank you

asked by lin on January 28, 2013
4. ## Chemistry

When 0.083 moles of lead(II) nitrate are dissolved in enough water to make 617 mililiters of solution, what is the molar concentration of nitrate ions? Answer in units of

asked by Rara on October 2, 2011
5. ## CHEMISTRY!!!!

Determine the pH at the equivalence point in the titration of 41.0 mL 0.096 M formic acid with 0.108 M NaOH at 25oC. Calculate the pH of a solution that is 0.22 M pyridinium ion (C5H5NH+) at 25oC.

asked by Michelle on March 5, 2015
6. ## calculus 2

Use Euler's method with a step size of 0.2 to estimate y(1), where y(x) is the solution of the initial value problem y' = 6x+y^2, y(0)=0. Round your final answer to 4 places, but keep more places on the intermediate steps for accuracy.

asked by TayB on April 11, 2016
7. ## Math clarification Reiny

This is the problem you helped me with. I was curious, do I write the solution set as (1 + i3ã3)/2, (1-i3ã3)/2 change it to the standard form first x^2 - x + 7 = 0 a=1, b=-1, c = 7 x = (1 } ã(1 - 4(1)(7))/2 = (1 } ã-27)/2 Your answer is an

asked by Sabrina on September 25, 2010
8. ## Math Reiny question

This is the problem you helped me with. I was curious, do I write the solution set as (1 + i3ã3)/2, (1-i3ã3)/2 change it to the standard form first x^2 - x + 7 = 0 a=1, b=-1, c = 7 x = (1 } ã(1 - 4(1)(7))/2 = (1 } ã-27)/2 Your answer is an

asked by Sabrina on September 24, 2010
9. ## child development

If a child is unable to connect to others because her parents do not show her love and acceptance what would be the appropriate solution for this situation? A. Change adult expectations. B. Help the child get her needs met. C. Get outside help. D. Use

asked by bev on August 25, 2015
10. ## math

A 75.0g sample of liquid contains 17.5% by mass of H3PO4 (molar mass = 98.0g/mol). If 215.0mL of Ba(OH)2 is needed to completely neutralize the acid, determine the concentration of the Ba(OH)2 solution used

asked by Anonymous on July 29, 2017
11. ## Chemistry

you are given two unlabelled colorless solutions: AgNO3(aq) and Ca(NO3)2. A)Which ion when added to each unlabelled solution would produce a precipitate with the calcium and silver ions? No clue what this question is asking. Can I get help?

asked by Sarah on October 18, 2017
12. ## Algebra

Graph the solution set of the system of inequalities and give the exact coordinates of the intersection points of the related equations: y>x^2 -8 X+y≤1, The closest points I'm getting is (-2.5,-1.8) and (2.5,-1.5) but I feel like they're incorrect

asked by Jen on November 24, 2017
13. ## Chemistry

When 0.046 moles of lead(II) nitrate are dissolved in enough water to make 485 milliliters of solution, what is the molar concentration of nitrate ions? Answer in units of M.

asked by Cheyenne on September 23, 2010
14. ## chemistry

There is a ball with a mass of 1000 lbs. It's turned into wire with a diameter of 3.12 x 10^-1 How long is the wire? This is my crazy chemistry teacher's idea of a test...and I don't even think there's a solution. HELP ME

asked by Molly on October 3, 2011
15. ## Solid Mensuration

In a circle with a diameter of 10m, a regular five-pointed star touching its circumference is inscribed. What is the area of the part not covered by the star? Pls help with a solution and a diagram. Thanks!

asked by Justine on April 18, 2016
16. ## Physics

If the average gauge pressure in the artery is 1.41E+4 Pa, what must be the minimum height, h of the bag in order to infuse glucose into the artery? Assume that the specific gravity of the solution is 1.04.

asked by Sam on April 20, 2016
17. ## science-chem

If I'm given 0.025 molar solution of Li2SO4(aq) and I have to find the concentration of each ion, how would I go about doing it? THANKS! My work (just li): 0.025M Li2SO4*(2MolLi/1MolLi2SO4)=.....Would that be right? I feel like there has to be one more

asked by Ally on September 17, 2009
18. ## chemistry

A 75.0g sample of liquid contains 17.5% by mass of H3PO4 (molar mass = 98.0g/mol). If 215.0mL of Ba(OH)2 is needed to completely neutralize the acid, determine the concentration of the Ba(OH)2 solution used

asked by TC on July 22, 2018
19. ## Math

what is the solution to (3 × 102) x (5 × 105), written in scientific notation? A.1.5 × 10^8 B.15 × 10^8 C.1.5 × 10^7 D.15 × 10^7 ben spent 2/3 of his allowance on video games. what is the fraction of his allowance expressed as a decimal. 0.6 0.7 0.16

asked by Brandon on October 30, 2018
20. ## physics

a tennis ball is served horizontally from 2.4 above the ground at 30 m/s the net is 12 m away and 0.9m high will be clear the net? a. 0.64m b. 1.62m c.2.72m d.none ans is option B .... but how? wanna solution..

asked by MCAT student on May 7, 2018
21. ## Chemistry

The freezing point of a 0.10m solution of mercury(I) nitrate is approximately -0.27 degrees celsius. Show that these data suggest that the formula of the mercury(I) ion is Hg2 2+

asked by Amy on March 6, 2011
22. ## Chemistry

A student actually used 0.847g sample of impure KHP and the endpoint was reached after 19.82 ml of sodium hydroxide solution was added, What is the percent KHP in the unknown to four significant figures.

asked by BEE on August 1, 2011
23. ## math , help

can someone show me how to solve this: directions: pivot once as indicated in each simplex tableau. Read the solution from the result. the number that is highlighted is row 2 column 3 which is the 5 the matrix is a 4 X 8 under column one it reads as:

asked by jas on June 13, 2007
24. ## Chemistry

A student actually used 0.847g sample of impure KHP and the endpoint was reached after 19.82 ml of sodium hydroxide solution was added, What is the percent KHP in the unknown to four significant figures.

asked by BEE on July 31, 2011
25. ## wildcat

Compound Interest: Suppose \$1,600 is invested in a savings account that pays 5% compounded semiannually, how much is in the account at the end of 11 2 years? having difficulties in finding a solution

asked by Lynn on September 17, 2012
26. ## Chemistry

What is the concentration of arsenate ions in 3.5 M solution of arsenic acid? The acid-dissociation constants of H3AsO4 are: Ka1 = 5.0 x 10-3 Ka2 = 9.3 x 10-8 Ka3 = 3.0 x 10-12 I can't figure out how to set up the question

asked by Kelly on March 18, 2015
27. ## Chemistry

A 1.516 M solution is made by dissolving 1.570 g of the compound in 0.2238 mol of water. Determine the molar mass and apparent molecular formula of the compound.

asked by Anonymous on November 4, 2014
28. ## Chemistry

A 0.130-mole quantity of CoCl2 is added to a liter of 1.20 M NH3 solution. What is the concentration of Co2 ions at equilibrium? Assume the formation constant of Co(NH3)62 is 5.0× 10^31.

29. ## Chemistry

Determine the pH of a solution that is prepared by mixing 100.0 mL of 0.125 M NaOH with 145 mL of 0.125 M CH3COOH (pKa = 4.75). Report your answer to 2 decimal places. Please help, I have no clue!!

asked by Andrew on November 23, 2007
30. ## Chemistry

A solution is prepared by adding 300 mL of 0.500 M NH3 and 100 mL of 0.500 M HCl. Assuming that the volumes are additive, what is the pH of the resulting mixture? Kb for ammonia is 1.8 x10 -5

asked by Taylor on October 4, 2010
31. ## Chemistry

A 0.130-mole quantity of CoCl2 is added to a liter of 1.20 M NH3 solution. What is the concentration of Co2 ions at equilibrium? Assume the formation constant of Co(NH3)62 is 5.0× 10^31.

32. ## chemistry

A 75.0g sample of liquid contains 17.5% by mass of H3PO4 (molar mass = 98.0g/mol). If 215.0mL of Ba(OH)2 is needed to completely neutralize the acid, determine the concentration of the Ba(OH)2 solution used

asked by ram on February 24, 2017
33. ## Math, Calculus

help Please... Differential Equations Problems... please give the complete solution, so that i can understand how it is derived... tnx in advance, god Bless... Here are the problems : 1.) y dx + (2x+3y)dy = 0 2.) (2xy + y^(2) ) dx - 2x^(2) dy = 0 ;y = e, x

asked by Huck on October 19, 2009
34. ## Chemistry

Like water, liquid ammonia undergoes autoionization: (a) Identify the Brønsted acids and Brønsted bases in this reaction. (b) What species correspond to H and OH and what is the condition for a neutral solution?

asked by sok on March 10, 2011
35. ## Math

Hi! My teacher wanted me to sketch the graph of solution set of each system. For the first question, she wants me to use the slope intercept form and the second question using a table of values, but, I'm a little lost. Can someone help? Thanks! 1.) 3x + 2y

asked by Heather on March 21, 2015
36. ## trig

hey. show 2sin(pi/14) is a solution to x^3-x^2-2x+1=0 and hint: let x=2sinu and sin(7u)=1 i can't seem to solve when i sub in the x value. how can i relate this to the seventh root of inifinity. i multiplu by sin^4 but they it just doesnt work.

asked by alice on April 23, 2010
37. ## chemistry

20 g NaOH are dissolved in 1 L H2O. What is the N of the NaOH solution

asked by nicole on May 6, 2015
38. ## chemistry

20 g NaOH are dissolved in 1 L H2O. What is the N of the NaOH solution?

asked by Anonymous on May 6, 2015
39. ## science(chemistry)

2 mL 1.5 M naoh and 1.5 mL 2 M naoh mixed solution's concentrate=?

asked by rajib on May 19, 2016
40. ## Calculus

Sketch the solution curves for y'=xy How do I sketch this??? Where do I start?

asked by Emma on October 13, 2009
41. ## broward

Calculate the molarity of 5.8 L of NaCl solution that contains 65 g of NaCl

asked by stacy on March 30, 2015
42. ## chemistry

A 0.039 M solution of a weak acid (HA) has a pH of 4.28. What is the Ka of the acid?

asked by Syahira on April 22, 2016
43. ## Chemistry

If the Ka of a monoprotic weak acid is 4.3*10^-6, what is the pH of a 0.16 M solution of this acid?

asked by Josh on July 24, 2011
44. ## Chemistry

If Ka for HNO2,=4.5x10-4, find the [H+] a 0.9 M HNO2 solution.

asked by Kathy on May 26, 2016
45. ## Algebra

Solve -3x-5 is greater than or equal to 16 Would the solution be x is less than or equal to -7?

asked by Anonymous on October 13, 2009
46. ## Chemistry

In 250 mL of a 0.35 M solution of NaOH, there are how many grams of NaOH?

asked by Hannah on November 24, 2014
47. ## chemistry

What is the pH of a 2.62 x 10 -1 M HCN solution ? NB the pKa for HCN = 9.212. 4.90 9.21 0.58 11.32 13.42

asked by Lucinda on May 27, 2010
48. ## Chemistry

The pH of a solution of hydrochloric acid is 1.97. What is the molarity of the acid?

asked by Anonymous on October 18, 2012
49. ## chemistry

How many grams of CaCl2 would be dissolved in 1.1 L of a 0.17 M solution of CaCl2?

asked by john on February 19, 2017
50. ## physical chemistry

if 10 litres of a solution of na2co3 contains 21.2g of na2co3, what is its strength?

asked by brock on October 20, 2011
51. ## algebra

Can you give me and example of an inequality and provide a value that may or may not be a solution to the inequality?

asked by C on April 5, 2008
52. ## Chemistry

You have 10.0 L of 1.2 M KNO3. What molarity would the KNO3 solution be if you were to take 2.5 L of it and dilute it to 10.0 L?

asked by Kay on March 6, 2013
53. ## math

what is the difference between a solution set and a replacement set

asked by cheryl on October 18, 2010
54. ## Trig

The set of solution(s) of 2 cos^2 (θ) - 13 cos(θ) + 6 = 0 that is(are) in the interval (0,π/2) is one of following a. {π/6} b. {π/3} c. {π/4} d. {π/3, π/6} e. {π/6, π/4}

asked by Lenny on December 13, 2011
55. ## algebra

Find values for m and b in the following system so that the solution to the system is (-3,4). 5x+7y=b mx+y=22

asked by Becky on December 26, 2007
56. ## chemistry

A 0.040M solution of a weak acid has a pH of 3.02 at 25°C . What is the value of Ka for the acid?

asked by darren on March 15, 2011
57. ## Chemistry

When you have 250. mL of a 2.80 M solution of HCl, how many moles of HCl do you have

asked by Kay on February 11, 2013
58. ## Chemistry

How many grams of 10% wt BaCl2 solution will be necessary to produce 5.6g BaCl2?

asked by ange on December 6, 2015
59. ## Calculus

Sketch the solution curves for y'=xy How do I sketch this??? Where do I start?

asked by Emma on October 12, 2009
60. ## chemistry

How would you prepare a standard solution of 1m HCL(5.6 of HCL is 1.18)?

asked by Joy on March 8, 2011
61. ## pre calculus honors

solve the system if possible | x+y+z = 15 | | < 7x+y+z = 75 | | | 3x+y-z=29 a. x=10,y=2,z=3 b. x=–10,y=–2,z=–3 c. x=3,y=10,z=–3 d. x=12,y=9,z=–3 e. no solution; inconsistent system

asked by evelyn on August 24, 2016
62. ## chemistry

Calculate the [CH3CO2H] in a solution if it has a pH 3.21. CH3CO2H = CH3CO2- + H+

63. ## Algebra

WRITE AN INEQUALITY AND PROVIDE A VALUE THAT MAY OR MAY NOT BE A SOLUTION TO THE INEQUALITY

asked by olabisi on August 5, 2008
64. ## Chemistry

how many ml of 0.200m NAOH solution contain 2.00g NaOH(MW =40.00

asked by Tapiwa on May 4, 2016
65. ## algebra

Can you give me and example of an inequality and provide a value that may or may not be a solution to the inequality?

asked by C on April 5, 2008
66. ## math

Write an inequality and provide a value that may or may not be a solution to the inequality.

asked by scooby9132002 on May 21, 2009
67. ## algebra

Write an inequality and provide a value that may or may not be a solution to the inequality.

asked by mary on January 15, 2009
68. ## Science

How many grams of H2SO4 are in 125 mL of a 3.00 M solution of H2SO4?

asked by Eli on November 4, 2014
69. ## Algebra/Math

How much dry substance is there if we have 150g of 8% of a solution of this substance.

asked by GeniusTigeress on February 20, 2017
70. ## science

If the Ka of a monoprotic weak acid is 8.3 × 10-6, what is the pH of a 0.28 M solution of this acid?

asked by candace on July 22, 2013
71. ## Chemistry

The pH of a 0.065 M solution of a weak base is 11.70. What is the value of Kb for this base?

asked by Brian on February 27, 2011
72. ## Chemistry

How many grams of NaBr are contained in 85.0 mL of a 2.10 M NaBr solution? I'm not sure how to go about this..

asked by Roxie on December 1, 2010
73. ## Chemistry

If the Ka of a monoprotic weak acid is 9.0 × 10-6, what is the pH of a 0.26 M solution of this acid?

asked by Sevy on October 25, 2011
74. ## math

Solve by substitution method 9x+6y=21-9x+y=35 What is the solution of the method?

asked by micheal on June 16, 2009
75. ## Chem 106

Calculate the grams of HNO3 in 35.0 ml of a 6.00 M HNO3 solution

asked by jessica on April 8, 2010
76. ## algebra 2

how do i work this 3x2-2x-8=0 the solution is -6 and 4 how do you work this out for my class

asked by kay on January 18, 2012
77. ## chemistry

A liter of 8 M NaOH solution contains how many grams of NaOH?

asked by a on January 14, 2010
78. ## CHEMISTRY

1. The use of a more dilute NaOH solution for the standardization of NaOH.

asked by MM on January 16, 2012
79. ## chemistry

For the weak acid HX, what is the pH of a 0.10 M solution if the acid is 4.0% ionized?

asked by cs on November 28, 2010
80. ## chemistry.

How many grams of H3PO4 are in 175 Ml of a 3.5 M solution of H3PO4?

asked by Denmark on November 15, 2009
81. ## Math

Write an inequality and provide a value that may or may not be a solution to the inequality.

asked by jay jay on September 3, 2008
82. ## chemistry

How many grams of NaOH are present in 5.0 mL of a 1.0% (m/v) NaOH solution?

asked by Rob on April 25, 2008
83. ## Maths

Pls Help(18m^2-8m) Solution 18m^-8m M+18^2/8=0 (m+18/8)^2=8m-324/64=0 ,...

84. ## algebra

what is the solution of the following system {3x + 3y =10 {-9x-9 =-30 Can you show step by step please.

asked by bowershe on December 10, 2013
85. ## maths steve reiny

Sqrt(x)^sqrt(x)=2 show solution step that all i need thanks

asked by Anonymous on November 2, 2016
86. ## chemistry

how many moles of NaCl are contained in 1.9L of a 1.7M NaCl solution

asked by nakisha on March 1, 2012
87. ## math

You have a 70% dextrose solution. How many grams of dextrose are in 400ml?

asked by melissa on March 9, 2008
88. ## math

if the domain is the set of integers, the solution set of x^2 -3x -4

asked by Anonymous on December 26, 2010
89. ## chemistry

The pH of a 1.2 M solution of an unknown weak base is 10.65. What is the Kb for the base?

asked by rodrigue on February 19, 2010
90. ## chemistry

What is Ka for 4-aminobenzoic acid if a 0.020 M solution of the acid has a pH of 3.31? a. 2.5 ´ 10-2 b. 2.0 ´ 10-2 c. 4.9 ´ 10-4 d. 1.2 ´ 10-5 e. 2.8 ´ 10-6

asked by james on May 30, 2010
91. ## science

A 0.513 M solution of a weak base has a pH of 11.4. What is the Kb of the base?

asked by Martha on September 9, 2010
92. ## Chem 121

How many grams of NaOH are present in 9.0 mL of a 8.0% (m/v) NaOH solution

asked by Barbara on July 26, 2011
93. ## Biology

You need 25ml of 2% milk solution (v/v. How much milk and water will you need?

asked by Anonymous on January 19, 2015
94. ## chemistry

How would you make a 1.0 L of 0.10M NaOH solution of 10.0M NaOH?

asked by Marilyn on April 6, 2011
95. ## college intermediate algebra

what is the step by step solution to 3x2y-11xy+8y

asked by Shatovia on November 14, 2010
96. ## more math needed

You have a 70% dextrose solution. How many grams of dextrose are in 400ml?

asked by Vicki on February 24, 2012
97. ## chemestry

How many grams of CaCl2 would be dissolved in 1.4 L of a 0.11 M solution of CaCl2?

asked by yanely on March 11, 2014
98. ## college

A solution that has more hydroxyl ions than hydrogen ions are

asked by Deanna on September 2, 2009
99. ## chemistry

A liter of 2M NaOH solution contains how many grams of NaOH?

asked by Victoria on January 27, 2010
100. ## Chemistry

What is the mass of a 8.64% (m/m) AlCl3 solution containing 7.59g AlCl3?

asked by Elaine on February 7, 2013