# Posts by Helper

Total # Posts: 1,842

**Calc.**

| x cos(x^2) dx | = integral symbol By half-angle cos^2 x = 1/2 (1 + cos 2x) | x 1/2 (1 + cos 2x) dx 1/2 | x + x cos 2x dx 1/2 | x dx + 1/2 | x cos 2x dx 1/4 x^2 + 1/2 | x cos 2x dx Integrate | x cos 2x dx by Integration by Parts u = x, dv = cos 2x dx du = dx, v = 1/2 sin 2x 1...

**Calc.**

S b= sqrt(Pi) a= 0 xcos(x^2)dx What is "S b = sqrt(Pi) a= 0" What are you integrating? Is it this? x cos(x^2) dx ? from a = 0 to b = (sqrt(pi))?

**Bobpursely**

Thank you, drwls!

**Bobpursely**

FYI-Many questions are under the name "Anonymous". If you expect a particular tutor to help you, you need to be more specific.

**Help**

sorry about the typo!

**Help**

Yes, x = 3 See your 1st post. I had a typo, and corrected it below.

**Help**

This problem was solved below for you. How many tutors do you need to solve this for you?

**college algebra**

1500sqrt(2)+1450 unless you use the value of (sqrt(2)), these two expressions cannot be added.

**Math**

Ignore above. I thought it was 3x = 1, not 3x - 8 = 1 x = 3

**Math**

Correct!

**Math**

(cubed root 3x-8)-1=0 Take the cube rt of both sides 3x - 1 = 0 3x = ? I'll leave this for you to finish

**Math correct or not**

Not correct

**Math**

Are you asking for the area of this box? A = Lw A = 2 2/3 * 2 2/3 A = 8/3 * 8/3 A = 64/9 = 7 1/9 sq ft

**algebra**

s = 4x - 3 V = s^3 V = (4x - 3)^3 V = (4x - 3)^2 (4x - 3) I leave the multiplication to you.

**finance**

This question asks "from your personal experiences". Post your personal experiences and a tutor will offer comments.

**7th grade math: Pythagorean Thereom**

It could be, 9 + 40 = 49 a^2 + b^2 = 41^2 a + b = 49 Solving simultaneously a = 9, b = 40 or a = 40, b = 9 41^2 = 9^2 + 40^2 1681 = 81 + 1600 1681 = 1681

**7th grade math: Pythagorean Thereom**

Do you mean that the two unknown sides total 49, or all three sides total 49?

**Gym**

Going up, down, diagonal what? Adding, multiplying, etc to equal 24? What exactly does the problem state to do?

**trig**

Correct!

**Precalc**

No solutions exist

**Algebra 1**

2x + 5y = 4 Add -2x to both sides 5y = -2x + 4 divide both sides by 5 y = -2/5 y + 4/5 So, slope m = -2/5 Perpendicular lines, the slopes are negative reciprocals of each other. Slope = -2/5 m1 * m2 = -1 -2/5 * m2 = -1 m2 = -1/(-2/5) m2 = 5/2 Now you have to find b, for the ...

**algebra**

R = 221.19x - 0.2x^2 R = 221.19 (273) - 0.2(273)^2 R = 221.19 (273) - 0.2(74,529) R = ?

**Math**

To understand this you really need to sketch this out. Think of the x/y axis on a graph, with the y-axis as North and the x-axis as East. Both boats are traveling from the North (top of the y-axis), toward East (down toward the x-axis). The first bearing, forms a 47 deg. angle...

**Exponents**

Meant to comment, If you square x^-2, x^-2 * x^-2 = x-4 = 1/x^4 1/^4 = 81 square root of both sides 1/x^2 = 9 You are back to the above.

**Exponents**

x^(-2) = 9 Since, x^(-2) = 1/x^2 1/x^2 = 9 Multiply both sides by x^2 1 = 9x^2 1/9 = x^2 square root of both sides + - 1/3 = x

**Math EASY**

Like Ms. Sue said. I just did this based on info you provided.

**Math EASY**

(83 + 3/5 + 5/5)/3 (83 + 60 + 100) = 243/3 = 81 81%

**adult education-Psycology?**

If you would like help in a timely manner please follow directions and put your school subject in the "School Subject" box.

**MATH**

If I am picturing this correctly, a right triangle is formed, with the hypotenuse c = 75 cm. Since the top of the wall is 5.4 m above ground, 5.4 - side a = height above ground to the roof edge. Angle A = 180 - (23 + 90) = 82 degrees sin 82 = op/hyp = a/c = a/75 0.9903 = a/75 ...

**arithmetic**

5/6 * 4 Since 4 = 4/1, you multiply the numerator of 5/6 times 4, and the denominator of 5/6 * 1 5/6 * 4/1 = 20/6 = 10/3

**5th math**

x = number of boys x + 4 = number of girls x + x + 4 = 30 2x + 4 = 30 2x = 26 x = 13 x = number of boys = 13 x + 4 = number of girls = 13 + 4 = 17 13 boys + 17 girls = 30

**5th grade**

Pat, I read that wrong. 77/35 * 285 = ?

**5th grade**

All that info and all the problem wants is the cost for 285? .77 each x 285 = ?

**5th math**

w = width, L = length Perimeter = 2w + 2L 60 = 2w + 2L 60 = 2(w + L) Divide both sides by 2 30 = w + L Since a square has equal sides and w + L = 30 15 + 15 = 30 So each side is 15 15 + 15 + 15 + 15 = 60 I don't know if a 5th grader does this type of problem like I did. If...

**Algebra 1**

2x + 5y = 4 Add -2x to both sides 5y = -2x + 4 divide both sides by 5 y = -2/5 y + 4/5 So, slope m = -2/5 Perpendicular lines, the slopes are negative reciprocals of each other. Slope = -2/5 m1 * m2 = -1 -2/5 * m2 = -1 m2 = -1/(-2/5) m2 = 5/2 Now you have to find b, for the ...

**Algebra 1**

Did you see the answer to your post below? Post your work so I can see where you are having trouble.

**5th math**

Mean is the average ADD the number of letters and divide by the number of numbers. 105 + 97 + 88 + 86 = sum Average = sum/4

**5th math**

28.5 min for 4 miles 28.5 min/4 mi = 7.125 min each mile So, this is your equation 4k = 28.5 k = 28.5/4

**algebra**

-4x - 12 = 0 Add 12 to both sides -4x - 12 + 12 = 0 + 12 -4x = 12 Divide both sides by -4 x = ?

**Algebra 1**

x + 6 = length of sidewalk x + 4 = width of sidewalk A = Lw A = (x + 6)(x + 4) (x + 6)(x + 4) = 39 Expand and solve for x

**pre algebra-math**

helper - please choose another 'Name' I've been using this name and it is very confusing when you use the same name. Thank you so much. Just put a number next to the name, if you want to use 'helper'.

**pre algebra-math**

yes^ please help 18/12 and 3/27

**...**

you mean 18/12 then the other question is 3/27!!!

**Algebra 1**

(6,7);6x+y=9. y = mx + b 6x + y = 9 y = -6x + 9 m = -6 m1*m2 = -1 -6*m2 = -1 m2 = 1/6 So, the slope of the perpendicular line is 1/6. y = 1/6 x + b Now find b with point (6,7). y = 1/6 x + b 7 = 1/6 (6) + b 7 = 6/6 + b 7 = 1 + b b = 6 y = 1/6 x + b y = 1/6 x + 6

**Algebra 1**

Your equation is not complete. 6x + = 9?

**ALGEBRA**

V = e^3 (e = edge) 64 = e^3 e = 4 Can you take it from here?

**Algebra**

Remaining angle = 180 - (55 + 47) Supplementary angles total 180 degrees You should be able to try this now.

**7th grade math**

Area = ((b1 + b2)/2)* h 4 = ((b1 + b2)/2)* 1 4 = ((b1 + b2)/2) Multiply both sides by 2 8 = b1 + b2 So, the sum of base1 and base2 = 8 I don't know what you mean by 'best numbers'?

**Algebra**

Find the mean (average) 1 + 2 + 4 + 5 + 6 + 8 + 9 + 10 + 10 = sum Average = sum/9 The median is the middle value, 6 mean - median = postive difference Then express this difference as a fraction

**Pre Calc**

If I am understanding this picture, a right triangle is formed with angle A = 50 degrees and side b = 23 (15 + 8). You need the length of a, which is the streetlamp. tan A = opp/adj = a/b = a/23 tan 50 = a/23 1.19 = a/23 Solve for a, for your answer

**math**

x = one angle 2x = largest angle 1/3 x = smallest angle x + 2x + 1/3 x = 180 Solve for x

**Reading APE**

Did you read this? Tell us what you think and someone will proof your answer.

**algbra**

You need more parentheses in your problem. t = (r + k)/(2w)? t = r + (k/(2w)) ? t = r + (k/2) w ? Or?

**Algebra**

Answer is 2a^(-4)c^4 a^6/a^10 = a^(6-10) = a^-4

**Precalc**

You're welcome!

**Precalc**

solve 5(2^(3x)) = 8 5(2^(3x)) = 8 2^3x = 8/5 2^3x = 1.6 take logarithms of both sides 3x log 2 = log 1.6 Divide both sides by 3 log 2 x = log 1.6/(3 log 2)

**Pre-Algebra**

2/3 m - 5 = n Multiply both sides by 3 2m - 15 = 3n 2m = 3n + 15 m = ?

**L Pre-Cal**

3x-5y+5=1 5x-2y+3z=0 7x-y+3z=0 Do you have a typo? 3x - 5y + 5? = 1 There is no z term in equation 1?

**pythagrean theorem**

Ms. Sue is correct. I get 12.5 too.

**math**

Convert a) through e) to addition expressions Change the sign to + and change the sign of the number to the opposite of what it is. a) -6 - 9 = -6 + (-9) b) -10 - (-12) = -10 + 12 Now you do c), d) and e)

**math**

m = (-1-3)/(2-(-4) You had 3, should be 2

**math**

A(-4,3) and B(2,-1) If you have points A(x1,y1) and B(x2,y2) Slope m = (y2 - y1)/(x2 - x1)

**Math**

V = lwh Divide both sides by lh w = V/lh

**math**

Assuming simple interest, I = PRT Interest = Principal x Rate x Time 525 = 3500(.06)T 525 = 210T T = ? years

**ALGEBRA/PLEASE HELP**

LCM = (1 - 2t)(1 + 2t)

**Algebra 1**

Put the line in slope-intercept form, y = mx + b m = slope, b = y-intercept

**Math**

r = 2s - 8 2s = r + 8 s = 1/2 r + 4

**geometry**

Without seeing the diagram, not enough info. You would have to give a description that would allow for the tutor to understand where exactly this cord is, among other things. Could you solve this problem if all you knew was the info you posted? Think about that when posting a ...

**math**

x = amount for 3 2/5 x = amount for 2 5(2/5 x) = amount for 1 x + 2/5 x + 5(2/5 x) = 102,000 Solve for x

**algebra2**

Yes, b is the missing variable. But 3a^2b^2x still does not = 6a^2b^2x 6a^2b^2x = 6a^2b^2x

**math**

Find the inverse of f and see if it is g.

**Math**

Then post your answer, and ask for the answer to be checked. Less work for the tutor's, to type "yes" or "no", then to type out how the problem is done.

**Math**

Can you do any of these type problems? Post your work where you are stuck and someone will help. Tutors will not do your homework.

**math**

See the 1st link below under Related Questions. This exact problem was answered.

**algebra**

a4b + a5b + 3 What factors do all expressions have in common? Answer, none This cannot be factored. All you could do is, a4b + a5b + 3 ab (4 + 5) + 3

**algebra**

and the cost is 55.00 labor is 4.00 ? How about some periods or commas. Sometimes, if tutors cannot make out your post, they move on to one that they can understand.

**Algebra 1**

(6,7);9x+y=6 Put in y = mx + b form 9x + y = 6 y = -9x + 6 So slope m = -9 Perpendicular lines have slopes that are negative reciprocals of each other. Meaning, m1 x m2 = -1 m1 = -9 -9 x m2 = -1 m2 = 1/9 So, the slope of the line will be 1/9 y = 1/9 x + b To find b, P(6,7) y...

**Algebra 1**

Do you need a line parallel to 9x + y = 6? Or? I'm happy you understand!! Good work.

**Algebra 1**

(-8,6); 2x = 3y + 4 3y = 2x - 4 y =(2/3)x - 4/3 So, slope m = 2/3 Use y = mx + b and P(-8,6) to find the equation parallel You know m = 2/3, so you have to find b. y = 2/3 x + b Put in x any y values and solve for b. 6 = 2/3 (-8) + b See how my equation is different than yours...

**Algebra 1**

Esther, see your post below at 3:11pm that I answered. I gave you detailed instructions on how to do this almost exact problem. You will never learn without attempting the problem yourself. Post all your work if your are stuck.

**algebra2**

Correct, (x - 3)(x + 5)

**algebra2**

x(x-3) + 5(x-3) What factors do both expressions have in common? Answer, (x-3) Can you factor now?

**algebra2**

Correct!!

**algebra2**

15Rx - 3Rex What factors do the two expressions have in common? Answer, 3Rx. Can you factor now?

**geometry**

Your question makes no sense. Please post the question exactly as it appears from your homework. If the side = 140 in., that is the length of that side. There is nothing to calculate for that side.

**math**

Your question is unclear. A can of lemonade concentrate has a capacity of 355 mL. Does this mean that the can of concentrate makes 355mL of lemonade ? Or, do you mean that 355mL combined with 4 cans of water, for the total amount of lemonade? If the second, without knowing the...

**Math**

y = -6x Slope m = -6 There is no y-intercept. Pick points to graph. y = -6x x = 0, y = 0 x = 1, y = -6 x = -1, y = 6 x = 2, y = -12 x = -2, y = 12 If you graph this, you will see a line through the origin. This line does not intersect the y-axis. Therefore, there is no y-...

**math**

17 2/3 + 23 1/4 Find the LCD for 2/3 and 1/4 LCD = 12 17 8/12 + 23 3/12 = ? Now, can you add them? Reduce the answer if necessary

**math**

-12 + r = -11 Add 12 to both sides 12 + 12 + r = -11 + 12 r = ?

**Algebra**

x = lbs of cheaper coffee 2.75x = value of cheaper 100 - x = lbs of better coffee 5(100 - x) = value of better 100 = lbs of mixture 3.90(100) = value of mixture 2.75x + 5(100 - x) = 3.90(100) Solve for x, lbs of cheaper 100 - x = lbs of better

**Algebra**

RT = D (Rate x Time = Distance) R = rate of southbound train 4 = time of southbound 4R = distance of southbound train R - 12 = rate of northbound train 4 = time of northbound 4(R - 12) = distance of northbound train Since the sum of distances = 528 4R + 4(R - 12) = 528 Solve ...

**math**

Do you mean 5 x 100 = 500 12 x 10 = 120 500 + 120 = 620

**Algebra**

d = number of dimes .10d = value of dimes 85 - d = number of quarters .25(85 - d) = value of quarters 0.10d + .25(85 - d) = 14.50 Solve for d, number of dimes 85 - d = number of quarters

**math**

100 cm = 1 meter 4.5 meter x 100 cm = 450 cm 450 cm / 4.5 cm = number of pieces of ribbon 450/4.5 = ?

**math**

x = attendance at Friday's game 2/3 x + 7000 = attendance at Thursday's game x + 2/3 x + 7000 = 77000 Solve for x - Fri 2/3 x + 7000 - Thur

**Algebra 1**

Parallel to 3x = 5y + 2 through P(-5,8) Parallel lines have equal slopes First, you need to put the given line in slope-intercept form, to find the slope. Slope-intercept form, y = mx + b m = slope b = y-intercept 3x = 5y + 2 To put in slope-intercept form, solve for y. 3x = ...

**algebra**

x = grams of copper 0.075x = value of copper 170 - x = grams of silver 0.925(170 - x) = value of silver (100 - 7.5 = 92.5) .16(170) = value of mixture 0.075x + 0.925(170 - x ) = 0.16(170) Solve for x, grams of copper (170 - x) = grams of silver

**maths**

If your equation is, x + 3x - 6.75 = 0 4x = 6.75 x = 1.6875 You should ALWAYS proofread your problem after posting to make sure it makes sense. I have no idea what the ? means.

**ctc**

Do you have a question?

**math**

From Diana's solution, 2.4 hrs = 2 hrs 24 min To convert .4 hrs to minutes, multiply by 60. .4 hrs * 60 min = 24 min