# Posts by helper

Total # Posts: 1,943

1. ### math

You're welcome :), we all make mistakes.
2. ### math

Miss Sue, I think you missed the "0" before 45 (0.045 not 0.45) 0.045 = 45/1000 = 9/200 = 0.045 So, the fraction is, 45/1000 = 9/200 (reduced to lowest terms) 0.045 * 100 = 4.5% So, the percent is, 4.5%
3. ### Measurment

Are 22, 16, and 28 the sides of this triangle? What is "a nine in the middle" mean? What does this "9" represent? Your question cannot be answered as worded. What exactly does your problem say or state to do?
4. ### denominators

You need to use parenthesis. If this is your problem v/(v+5)+v/3 = -4/(v+5) Multiply both sides by 3(v+5) 3v + v(v + 5) = -12 3v + v^2 + 5v = 12 v^2 + 8v + 12 = 0 (v + 2)(v + 6) v = -6 or v = -2 Make sure you check the solutions in the original equation. I have NOT checked the...
5. ### Math

W = width W + 42 = length P = 2W + 2L 228 = 2(W) + 2(W + 42) Solve for W W + 42 = Length
6. ### Math

x = hrs farming y = hrs babysitting 10x + 5y >= 150 x + y <= 25 Solve the system
7. ### algebra

Parallel lines have equal slopes. Equations in the form y = mx + b m = slope, b = y-intercept Your equation, y = 1/2 x + 2.3 Do you know the slope now?
8. ### math

Circumference, C = 2 pi r or, C = pi d C = 2 pi r C = 2(3.24)(100) C = 628 feet for one lap 5280 * 2 miles = 10,560 feet 10560/628 = ? = laps in 2 mile
9. ### Math

tan -120 = (sqrt(3)) = 1.73205 coterminal with 240 deg in QIII so positive reference angle is 60 Where did you get - 0.71312301 Are you using a cal. set to the wrong setting, rads vs degrees?
10. ### Geometry-Please check my answers

Both your answers are correct.
11. ### Algebra 2

3x^2 + 1 + (-3x)/(x^2 - 3) Yes, your answer is correct, but I was taught that the remainder is expressed as, (-3x)/(x^2 - 3)
12. ### Geometry-Please check

http://www.jiskha.com/display.cgi?id=1299028007
13. ### calculus

Ignore my response. I completely misunderstood the question.(:
14. ### calculus

I think I read the question wrong. I thought the question wanted the slope of the tangent of f(x) at (1,-5) and the two equations at this point.
15. ### calculus

y = x^2 - 2 f' = 2x P(1,-5) f' = slope m = 2(1) = 2 Equation of the line tangent at P(1,-5) m = 2 y = mx + b -5 = 2(1) + b -5 = 2 + b b = -7 Equation of the tangent line is, y = 2x - 7 2x - y = 7 Equation of the normal line at P(1,-5) (The normal line is the line that ...
16. ### accounting

Post your question, but I've noticed that there are not many experts here for accounting questions (depending on the specific question). Depending, I might be able to help, depending on how involved and the specific area involved. Someone might be able to point you in the ...
17. ### Algebra 2

You have to do polynomial long division. I can't layout the problem here because of the alignment of columns and such. See this website. It explains in detail how to do this. I'll check your answer if you post it. Good luck :) http://www.purplemath.com/modules/polydiv2...
18. ### geometry

See this post. Only the side length is different. Same method is used. http://www.jiskha.com/display.cgi?id=1298927532
19. ### Algebra 2

You need parenthesis. I'll assume your problem is, x/(x+1) + 5/x = 1/(x^2 + x) x/(x+1) + 5/x = 1/(x(x + 1)) Multiply both sides by x(x + 1) x^2 + 5(x + 1) = 1 x^2 + 5x + 5 = 1 x^2 + 5x + 4 = 0 (x + 1)(x + 4) = 0 x = -1 or x = -4 Make sure you check both answers in the ...
20. ### calculus

| = integration symbol | u dv = uv - | v du | arctan(4t) dt u = arctan(4t) du = 4/(16t^2 + 1) dt dv = dt v = t It should look like this, = t arctan(4t) - | 4t/(16t^2 + 1) dt After you set that up, substitute w = 16t^2 + 1 dw = 32t dt 1/32 dw = t dt Then, the integration should...
21. ### math algebra1

x = Janet's distance to office 2x - 1 = Lynn's distance to office x + 2x - 1 = 8 3x = 9 x = 3 x = 3 mi from Janet's house to office 2x - 1 = 5 miles Lynn's house to office
22. ### Algebra 1

You're welcome :)
23. ### Algebra 1

y = height = -16t^2 + 63t + 4 The vertex of this parabola is called the maximum point. Vertex = -b/2a Vertex = -63/(2(-16)) Vertex = t value = 1.96875 So, the maximum value for t seconds is 1.96875 y = height = -16t^2 + 63t + 4 t = 1.96875 y = -16(1.96875)^2 + 63(1.96875) + 4 ...
24. ### math

Assuming he spent all his money, x = Money he started with 1/3 x = spent on hat 1/6 x = spent on socks 12 = spent on a tie Total spent = 1/3 x + 1/6 x + 12 Total spent = 2/6 x + 1/6 x + 12 Total spent = 3/6 x + 12 Money he started with - Total spent = 0 x - (3/6 x + 12) = 0 6/...
25. ### Math 10+

Or, do you mean 2^(-3) = 1/(2)^3 = 1/8
26. ### Math 10+

1/8 = 0.125 x^(0.125)
27. ### math

The diagonal of a square forms two 45-45-90 triangles. The sides of a 45-45-90 triangle are in the ratio, a : b : hypotenuse x : x : x(sqrt(2)) The diagonal is the hypotenuse of this 45-45-90 triangle. Side = 7 7 * (sqrt(2)) = ?

What is ã ?

What is ã ?
30. ### Math/ Trade & Cash discounts

You're welcome! I hope I'm right. :) The problem is so wordy, so at first, I wasn't sure if more was expected. Good luck!
31. ### Math/ Trade & Cash discounts

1. Looks right. 2. I'm not sure why you subtracted the \$7000. first. The problem says 0.18 on orders of at least 22,000 units? 22,000 * 3.00 = 66,000 22,000 * 2.82 = 62,040 66,000 - 62,040 = 3,960 rebate 3960/66000 = 0.06 * 100 = 6% discount 3. 30,000 * 3 = 90,000 30,000...
32. ### Math/ Trade & Cash discounts

What exactly is your question? You show work and answers for all 4 questions. Are your answers correct? Are you asking for someone to check your work because you don't know if the answers you have listed are correct? You need to ask specific questions.
33. ### maths

Is this what you don't understand? 45% = 45/100 = 0.45
34. ### algebra

If this is what you mean, cube root = cr (cr(81)) = (cr(27))*(cr(3)) (cr(81)) = 3*(cr(3)) (cr(81)) = 3(cr(3)) This can be written as 81^(1/3) = 3(3^(1/3)) 81^(1/3) = (3^(3/3)*(3^(1/3)) 81^(1/3) = 3^(4/3)
35. ### Algebra

(sqrt(xyz))^3 (sqrt(xyz))*(sqrt(xyz))*(sqrt(xyz)) xyz(sqrt(xyz)) This can be written as, ((xyz)^(1/2))^3 = (xyz)^(3/2)
36. ### geometry

What is the figure and where are these segments? (AB, BC, AD, CD) located on this figure?
37. ### algebra

Find the area of a rectangle if three of its corners are (-0.1,-3.4), (-7.9,-3.4), and (-0.1,6.8). You are given 3 points of the rectangle. You need to find the 4th point. Rectangle ABCD, labeled clockwise from the bottom horizontal segment. A(-0.1, -3.4) B(-7.9, -3.4) C(-7.9...
38. ### algbra

drwls gave you the equation above. "You therefore have a horizontal line with equation" y = 18.1 points (-6.2,18.1) and (-3.4,18.1) As drwls said above, "The slope is zero and the y-intercept is 18.1." The slope intercept form of an equation is, y = mx + b ...
39. ### geometrY

Shannon, I'm very sorry. The set-up is wrong (1st line), but the rest is correct. I have no idea where I got that first line. http://member.tripod.com/~BDaugherty/GCSEMaths/shapes.html In the picture, the ratio is T/30 = 2/3 3T = 60 T = 20 Your problem, with the corrected ...
40. ### algebra 2--duplicate problem

Answered below.
41. ### algebra 2

6r^2 + 13rd + 6d^2 (3r + 2d)(2r + 3d)
42. ### algebra 2

6r^2 + 13rd + 6b^2 Cannot be factored. I don't think that is the equation. Are you sure you don't have a couple typos?
43. ### Math(Urgent)

Yes, your derivative is correct.
44. ### Mathematics

y = 1/2 x - 2 In the 2nd column all of the points have x = +6 y = 1/2 x - 2 y = 1/2(6) - 2 y = 6/2 - 2 y = 3 - 2 y = 1 Therefore, none of the choices are correct (since none of the points have y = 1). I think you have a typo because if I use x = -6 y = 1/2 x - 2 y = 1/2(-6) - ...
45. ### Mathematics

16 oz = 1 pound 16.5 lbs * 16 oz/lb = 264 oz Each paper = 0.55 oz 264/0.55 = ? number of papers
46. ### geometrY

http://member.tripod.com/~BDaugherty/GCSEMaths/shapes.html See the last picture at the bottom of this web page (for a pic of this exact problem). Using ratios, Tree height = T 15/66 = 6.33/T 15T = 512.73 T = 34.182 T = 34.182
47. ### Calculus

Correction for above, | = integrate symbol y = x^3 y^3 = x, y = x^(1/3) Using the formula pi | (f(x))^2 - (g(x))^2 dx pi | x^(1/3)^2 - (x^3)^2 dx pi | x^(2/3) - (x^6) dx pi ( 3/5 x^(5/3) - 1/7 x^7 ) When I evaluated from 0 to 1, I got, 16/35 pi
48. ### Calculus

| = integrate symbol y = x^3 y^3 = x, y = x^(1/3) Using the formula pi | (f(x))^2 - (g(x))^2 dx pi | (x^3)^2 - x^(1/3)^2 dx pi | (x^6) - x^(2/3) dx pi ( 1/7 x^7 - 3/5 x^(5/3)) When I evaluated from 0 to 1, I got, - 16/35 pi
49. ### algebra

Equation passing through the points (2,5) and ( 7,-3) Slope m = (-3 - 5)/(7 - 2) m = -8/5 y = mx + b y = -8/5 x + b Using point, (2, 5) to find b y = -8/5 x + b 5 = -8/5(2) + b 5 = -16/5 + b b = 5 + 16/5 b = 25/5 + 16/5 b = 41/5 y = -8/5 x + 41/5 In the form, y = mx + b b = y-...
50. ### college algebra

135 = 12.5(0.2t - 1) + 19t Solve for t
51. ### math-calc

As typed, without parenthesis f(x) = x/x + 1 f' = 0
52. ### ALGEBRA

http://www.purplemath.com/modules/graphlin.htm I'm not sure of your question. Do you know how to graph an equation? Is it because there are fractions? If because of fractions, convert to decimals and estimate as best you can. Your equation would be, y = -1.6 x + 8.2
53. ### algebra-Ann please edit your problem

What is "3ã" ? And please use parentheses if necessary.
54. ### math

See link. This exact problem was solved there. http://www.jiskha.com/display.cgi?id=1236980230
55. ### math

Please don't repost a question just asked. Be patient for an answer. Tutors volunteer their time and sometimes it can take awhile for your post to be answered. See your original post.
56. ### college algebra-Ann, edit your problem

What is "4ã" ? And please use parentheses if necessary.
57. ### algebra-Mike, edit your problem

What is "3ã" Please use parentheses if necessary.
58. ### algebra-Mike, edit your problem

What is "5ã" Please use parentheses if necessary.
59. ### algebra-Mike, edit your problem

What is "3ã" ? Please use parentheses if necessary.
60. ### math

3yrs OLDER than his brother, so you would add + 3 B. 2b + 3
61. ### math

Which do you think it is? Hint b = brother's age 2b = twice the brother's age
62. ### math

If you sketch this you will see a right triangle is formed. a = 8 b = 6 c = hypotenuse Use the Pythagorean theorem c^2 = a^2 + b^2 Solve for c, road to Bobby's house
63. ### Calculus 1

x^7 + y^7 = 8xy 7x^6 + 7y^6 y' = 8y + 8x y' 8x y' - 7y^6 y' = 7x^6 - 8y y'(8x - 7y^6) = 7x^6 - 8y y' = (7x^6 - 8y)/(8x - 7y^6)
64. ### geometry

Formula for long diameter (vertex to opposite vertex), d = (2 * side length * sin 67.5)/(sin 45) Formula for short diameter (one side to opposite side) d = ((2 * side length)/(sqrt(2))) + side length I'll do short diameter, d = (2 * 48)/(sqrt2)) + 48 d = (96)/(1.4142) + 48...
65. ### calculus

Like I said, more than one way to do this. I suggest follow Reiny's way.
66. ### calculus

Thanks Reiny. Nicky, depending on your approach, you need to use both the product rule and the chain rule (more than once). It's easy to get lost in this problem. What exactly do you not understand? Have you tried setting the problem up? One approach, start with the ...
67. ### calculus

Just making sure. Do you mean e^(8x^4) or e(8x^4) I've never see "e" referred to "exp" on this site, but I haven't been here long.

What is exp?
69. ### math

48a^2 + 4ab - 140b^2 Factor out 4 4(12a^2 + ab - 35b^2) 4(3a - 5b)(4a + 7b)
70. ### geometry

What is the figure? Depending on what the figure is, where is AC and BC ?
71. ### math--To MathMate

In regards to your reply to the problem that Daniel posted (f'(-pi)). I really appreciate you (and Reiny) taking the time to confirm that my answer was correct. I don't usually answer unless I am absolutely sure an answer is correct (I don't want to give wrong ...
72. ### calculus

All the online integration calculators I tried said that this cannot be integrated. Recheck your problem.
73. ### Math

80 mg = 0.08 grams 4 tablets x 20mg ea = 80 mg Looks good :)
74. ### MATH(CALCULUS)

Thank you so much Reiny.
75. ### MATH(CALCULUS)

Did you find f'(x) first? I just read your earlier post and you said you plugged -pi into 12x/(sinx+cosx) . You have to find f' first, then plug in (-pi). The derivative, f' is, (12(x sin x + sin x - x cos x + cos x)/ (sin x + cos x)^2 Then you plug in (-pi) You ...
76. ### Math

1 foot = 0.3048 meters 100 = ? meters
77. ### last question!!need help!!

Thanks so much MathMath. I did this problem so many times. After all the time I spent on this it's nice to have confirmation that my answer is correct. If Reiny reads this the same goes to you.
78. ### last question!!need help!!

f(x)=12x/(sinx+cosx) The derivative, f ' is, (12(x sin x + sin x - x cos x + cos x)/ (sin x + cos x)^2 Now you have to plug in (-pi) for x. I got -12 - 12pi (my post above answer), but, like I said, I did it really quick. It's late so I'm more apt to make a mistake...
79. ### last question!!need help!!

Is the answer -12 - 12pi? I did this real quick, and don't have time to post all the work or to double check my work, so I'm not positive this is correct. I can look at this more in the morning or maybe another tutor will answer.
80. ### last question!!need help!!

Did you read my post just above yours? In your first post asking this question, the one that MathMate answered 12pi, you had the problem as, f(x)=12x/sinx+cosx find f(-pie) Now you have, f(x)=12x/sinx+cosx find f'(-pie) f and f' are different. f' is the derivative...
81. ### last question!!need help!!

I think I see your problem. In prior posts you had, f(x)=12x/sinx+cosx find f(-pie) Now, you have f', the derivative. f'(-pie). Which is it?
82. ### last question!!need help!!

Please see your prior post. If you know the answer, why are you asking? Also, it would help if you posted the answer you think it is, then a tutor might have a better understanding of what is maybe being misunderstood.
83. ### need some help!!!

From your previous post, which MathMate answered. f(x) = 12x/(sinx + cosx) for -pi calculus-correction - MathMate, Thursday, February 24, 2011 at 9:45pm The required problem was f(-π) = 12(-π)/(0+(-1)) = 12π 12pi is the answer. You have said that this is not the...
84. ### Algebra 2

Pasted from previous post by PsyDag, Since it is not an equation, I cannot solve it for you, but I can help you to simplify it. Get rid of the fractions by multiplying everything by 16. I corrected the -1 to +1. x^4 + 6x^3 + 2x^2 + 16 - 9x^4 + 14x^2 - 16 Combine like terms. If...
85. ### Algebra

The slope-intercept form of an equation is, y = mx + b m = the slope b = the y-intercept You need to solve your equation for y, for the equation to be in the slope-intercept form. 3y = 2x - 9 Divide both sides by 3, y = 2/3 x - 9/3 y = 2/3 x - 3 Now, the equation is in the ...
86. ### Math

L x W x H 18 x 14 x 8 Room Perimeter P = 2W + 2L P = 2(14) + 2 (18) P = 28 + 36 P = 64 Perimeter * Height P = 64, H = 8 Area to paint = 64 * 8 A = 512 sq ft 512 sq ft/256 sq ft paint coverage = gal of paint needed 512/256 = 2 gals per coat 2 gals/coat * 2 coats = ? ttl gals ...
87. ### math

Distance, D = Rate, R * Time, T D = y R = 15 fps T = x seconds D = RT y = 15x
88. ### geometry

First, you need to graph this triangle. Then, use the distance formula to find the distance between points (length of the sides). Area A = 1/2 bh
89. ### Math

Also, I just noticed, Type A contains (????HOW MANY) ounces of oats and (????HOW MANY)ounces of corn per pound. Type B contains (????HOW MANY)ounces of oats and (????HOW ANY)ounces of corn per pound.
90. ### Math--Shell Missing Info

Please recheck your problem, your are missing information. Type A and Type B are both oats and corn mixtures. Is this correct? The farmer wants to combine the two feeds so that the resulting mixture has at least (????HOW MANY POUNDS) pounds of oats and at least(????HOW MANY ...
91. ### math

x = amount invested at 6% y = amount invested at 8% 0.06x = interest at 0.06 0.08y = interest at 0.08 Solve simultaneously, x + y = 6400 0.08y = 2(0.06x) x = \$2560 y = \$3840 \$153.60 = 6% int \$307.20 = 8% int
92. ### Maths

A. The circumference of a circle is the actual length around the circle. Circumference C = 2 pi r r = 30, pi = 3.14 C = (2)(3.14)(30) C = 60(3.14) C = 188.4 for 1 lap 6 laps = 6 * C 6 laps = 6 * 188.4 meters 6 laps = ? meters B. P = 2w + 2L w = 37 cm./100 = 0.37 m L = 5.2 m P...
93. ### S.P

I = PRT (Interest = Principal*Rate*Time) I = 30,000 * 0.07 * 4 I = ?
94. ### math !!!! :O

This exact question was answered earlier today. See link. http://www.jiskha.com/display.cgi?id=1298550296
95. ### math

3x^2 y - 5xy + 12x y^2 - 5x y^2 - 4xy 3x^2 y + 7x y^2 - 9xy
96. ### trig

360 deg = circle 360/6 = 60 deg 60 deg * pi/360 = 60pi/360 = pi/3 rads
97. ### Algebra 1

x = Rate without wind y = Rate of the wind T = D/R 6 = 3000/(x - y) 6(x - y) = 3000 6x - 6y = 3000 5 = 3000/(x + y) 5(x + y) = 3000 5x + 5y = 3000 Solve simultaneously, 6x - 6y = 3000 5x + 5y = 3000 5 *(6x - 6y = 3000)= 30x - 30y = 15,000 6 *(5x + 5y = 3000)= 30x + 30y = 18,...
98. ### math-Mathmate could you look at please

I was working on this at the same tiime as you, but I arrived at a different answer. x = amt Tierra had 2x/5 = amt Tierra spent 3x/5 = amt Tierra had left y = amt Alex had 4x/5 = amt Alex spent y - 4x/5 = amt Alex had left z = amt Nico had \$40 = amt Nico spent z - 40 = amt ...
99. ### math

I = PRT (Interest, I = Principal, P * Rate, R * Time, T P = 30,000 R = 7% = 0.07 T = 4 I = 30,000 * 0.07 * 4 I = 2100 * 4 I = 8400

h/-6 >= 5