# Posts by Helper

Total # Posts: 1,842

**Math**

Try an example to see if this is true. f(x) = 3x - 1 So, f(x) has y-intercept = -1 To find inverse of f(x), y = 3x - 1 x = 1/3 y + 1/3 y = 1/3 x + 1/3 f^-1 = 1/3 x + 1/3 To find x-intercept, y = 1/3 x + 1/3 0 = 1/3 x + 1/3 -1/3 = 1/3 x x = -1 So, f^-1 has an x-intercept = -1. ...

**Trig**

Coterminal A = A + k*360 To find a positive coterminal angle A = -240 Coterminal A = -240 + 360 Coterminal A = 120 To find a negative coterminal angle A = -240 Coterminal A = -240 - 360 Coterminal A = -600

**geometry honors**

V = 1/3 bh V = 64 h = 16 b = area of base 64 = 1/3 (16)b Solve for b, area of the base

**business accounting**

Actually, the above probably isn't what you need.

**business accounting**

From productivity501 "Maslow said that people start with the lowest level of this hierarchy and that their basic motivation comes from trying to meet their needs sequentially at each level. Any time their needs aren’t being met, their motivation always reverts to ...

**geometry**

1st Box V = Lwh V = 9 * 6 * 24 V = 1296 2nd box V = 1/2 (1296) = 648 V = Lwh 648 = 6(4)h Solve for h

**algebra**

You're welcome :)

**algebra**

2x+(x-y)^3 when x=9 and y=7 2(9) + (9 - 7)^3 18 + (2)^3 18 + 8 = ? Where were you having a problem?

**physics**

It would be Mars Weight/Earth Weight. So 3.71/9.8 which is 0.37857142857. And the 3 sig figs it would be 0.379

**math**

ratio of 8/9,quotient of 8/19,percent of 8/19. Ratio 8/9 is 8 : 9 Quotient 8/19 = 0.42105 Percent 8/19 = 42.11% In case ratio should be 8/19, 8 : 19

**algebra**

35+ 6 x < 20 -2 35 + 6x < 18 6x < -17 x < -17/6

**Algebra**

D = RT (Distance = Rate x Time) 50 = rate going T = time going 50T = distance going 45 = rate returning T + .5 = time returning (30/60 = .5h) 45(T + .5) = distance returning Distances are equal 50T = 45(T + .5) 50T = 45T + 22.5 5T = 22.5 T = 4.5 h 50T = distance going 50(4.5...

**pre-algebra**

What is the original problem? What does the problem state to do? You could write this as, y = 3(x + 7) Depending on your problem y = 3x + 21 is acceptable, especially if you are learning slope-intercept form of an equation. But you wouldn't be wrong to write this as, (if ...

**Algebra II**

No, y = -1 is an extraneous solution. y = 1, is the answer.

**Algebra II**

One answer, x = 6. .5 or 1/2 is an extraneous solution (not a valid solution). If you are asked specifically if there are any extraneous solutions, then you would list it as such. I've never had a problem ask for extraneous solutions, since it's not a solution to the ...

**Algebra II**

6 is correct. If you check your answers, you will find that .5 (1/2) is not a solution. You must always check your answers in the original problem.

**Math**

Where are the choices? w = width 2.25w = length Perimeter P = 2w + 2L P = 2w + 2(2.25w) P = 2w + 4.5w P = 6.5w

**beginning algebra**

-8w + uw + vu - 8v -8w + uw + uv - 8v w(-8 + u) + v(u - 8) w(u - 8) + v(u - 8) (u - 8)(w + v)

**geometry**

The measure of the altitude drawn from the vertex of the right angle of a right triangle to its hypotenuse is the geometric mean between the measures of the two segments of the hypotenuse. Triangle ABC, where A is the vertex, CB is the hypotenuse, and AD is the altitude. AD = ...

**Math**

I don't understand your question. What do you need to do with this list of numbers?

**Math**

A = bh A = 2b * 2h A = 4bh Area would be quadrupled (4 times as much in size).

**algebra**

y = -4x - 2 For x = 1, y = -4(1) - 2 y = -4 - 2 y = -6 Now do the same for (-1) and (-3).

**algebra 1**

I can't graph this for you here. Put "solving systems of inequalities" in google and click on the second link (the one with 'purplemath' in the address). This website gives an example of how to graph and solve inequalities.

**Calculus**

f(x)= 2x^3 - 2x^2 + 1 Find the derivative f' = 6x^2 - 4x The derivative is the slope of a tangent line to a curve, in this case, at (1,1). slope m = 6x^2 - 4x at (1,1) m = 6(1^2) - 4(1) m = 6 - 4 = 2 Using the form of the equation as, y = mx + b, m = 2 y = 2x + b To find b...

**pre-algebra**

It depends on what the problem asks for. If the equation was, 3x + 21 = 0 3(x + 7) = 0 x + 7 = 0 But, the equation is y = 3x + 21. If, the problem said to factor, this could be written as y = 3(x + 7) But, I don't know what her problem is looking for.

**pre-algebra**

y = 3x + 21 is in the slope-intercept equation form (y = mx + b). This equation cannot be simplified. It's as good as it gets.

**math**

1 mile = 5280 feet 5 days * 24h * 60 min * 60 sec = 432,000 sec D = RT, Rate = Distance/Time Rate = 5280/432,000 = 0.0122 ft/sec

**Calc**

derivative of (x^2+14)/x f(x)/g(x) = (g(x)*f' - f(x)*g')/(g(x))^2 (x(2x) - (x^2 + 14)*1)/x^2 (2x^2 - x^2 - 14)/x^2 (x^2 - 14)/x^2

**math**

x = number of goats x = goat heads 4x = goat legs 2x = number of ducks 2x = duck heads 2(2x) = 4x = duck legs x + 4x + 2x + 4x = 99 11x = 99 x = 9 x = 9 = number of goats 2x = 18 = number of ducks

**Math**

(2x + 9)(x - 6) = 0 This is already factored. 2x + 9 = 0 and x - 6 = 0 2x = -9 x = -9/2 x - 6 = 0 x = 6 x = -9/2, and x = 6

**Math**

I don't know why you have four answers, A,B,C, and D? Are you not answering i,ii, and iii ? i) .15 * 385 = 57.75 = 58 ii) Ratio portable media theft : hard copy theft 20% : 3% = .20/.03 = 6.67 iii) 4.13 mil govern ID no. Total people 110 mil (from b.) 4.13/110 = 3.75%

**pre-algebra-is my answer right**

Yes, those points are on that line.

**math**

s = son's age 3s + 5 = Nathan's age

**Math**

Correct

**Math**

(3x^2-8x^3+4x)-(9x^2-x^3+x)+4(6x-7) 3x^2-8x^3+4x -9x^2 + x^3 - x + 24x - 28 -7x^3 - 6x^2 + 27x - 28

**finance**

Beg. Inventory---300 units---11 ea--$3300 Produced---------650 units---12 ea--$7800 Total------------950 units--------$11,100 SOLD--LIFO (Last-in-first-out) From Beg. Inv----50 units--11 ea---$550 From Produced---650 units--12 ea--$7800 Total-----------700 units---------$8350 ...

**8th grade math**

6000 tons nachos 1.25 oz/serving 3.5 serving/person 3.5 serving * 1.25 oz = 4.375 oz/person 2000 lb/ton * 6000 tons = 12,000,000 lbs 12,000,000 lbs * 16 oz/lb = 192,000,000 oz 91,385 people * 4.375 oz/person = 399,809.3750 oz consumed 399,809.3750 oz consumed/192,000,000 oz = ...

**4th grade math**

I am not sure if a 4th grader would solve the problem as follows. x = apple slices 3x = orange slices x + 3x = 32 4x = 32 x = 8 x = 8 apple slices 3x = 3(8) = 24 24 + 8 = 32

**math**

n + n = 8 1/2 2n = 8 1/2 8 1/2 = 8.5 n = 8.5/2 n = ?

**intermediate algebra**

x = no. lbs of 6.50 nuts 6.50x = value of 6.50 nuts 50 - x = no. lbs of 8.00 nuts 8.00(50 - x) = value of 8.00 nuts 7.40(50) = value of mixture 6.50x + 8.00(50 - x) = 7.40(50) Solve for x, lbs of 6.50 nuts 50 - x = lbs of 8.00 nuts

**math**

1/4 of 280 = 70 = 25% (70/280 * 100) Note 1/4 = 25% (1/4 * 100)

**math**

n = total payments or periods Since it is compounded 6 times a year (unusual) n would be, 6 yrs * 6 times a yr = 36 Rate per period, r would be 0.08/6 = 0.0133

**math**

Here is the formula A = P * (r(1+r)^n)/((1+r)^n - 1) Just plug in your numbers A = Payment/period P = Principal r = Rate/period n = Total of payments or periods If you post your answer I can check it for you.

**calc**

Instantaneous velocity, v is the derivative f'(t). 8x^2 - 4x + 1 v = f' = 16x - 4 at x = 3 16(3) - 4 = ?

**math**

You need to answer drwls questions above so he/she can help you.

**math**

Is this your problem? 4|3 - 2x^6| - 3^2 = ? I think you must have copied this wrong. This problem, as typed, is not easy to solve. I used an online calculator and there are 12 different roots for x (4 real and 10 complex. Re-check your problem.

**math please help?**

x = amount invested .07x + .10x = 850 Solve for x, amount invested

**math**

You have to factor to solve. a^5 + 6a^4 + 5a^3 = 0 a^3(a + 1)(a + 5) = 0 a^3 = 0 a = 0 a + 1 = 0 a = -1 a + 5 = 0 a = -5 Do the other problems the same to solve.

**math**

8^(-7/3) = (cube rt 8)^-7 = 2^-7 = 1/128

**math**

(2.6 * 10)^8 = 26^8 = 208,827,064,576

**Math**

4x - 3y = 6 (0,2) x = 0, y = 2 4x - 3y = 6 4(0) - 3(2) = 6 0 - 6 = 6 -6 not= 6 This means that (0,2) is not a solution.

**Math**

27,000 in 3yr, 9%/yr compounded quarterly R = Ai/(1 + i)^n - 1 R = Payment A = Total needed = 27,000 n = Number of payments = 4 * 3 = 12 i = Interest rate = 0.09/4 = 0.0225 R = 27000(0.0225)/((1 + 0.0225)^12 - 1) R = 607.50/((1.0225)^12 - 1) R = 607.50/(1.30605 - 1) R = 607.50...

**math**

u/5 = 1.9 multiply both sides by 5 u = 9.5

**taxes**

Not sure if this will be readable. First set of dates is for date filed. Second set of dates is for refund deposited. return (by 11:00 am) Deposit Check between… Sent* Mailed* Jan 14 and Jan 20, 2011 Jan 28, 2011 Feb 4, 2011 Jan 20 and Jan 27, 2011 Feb 4, 2011 Feb 11, ...

**algebra**

ax/b + cx/d = e Multiply both sides by bd adx + bcx = bde x(ad + bc) = bde x = bde/(ad + bc)

**math**

3x^2 + 5x - 12 = 0 This cannot be factored This can be solved by completing the square or using the quadratic formula. (3x + 4)(x - 3) = 3x^2 - 5x - 12 Does not equal 3x^2 + 5x - 12

**Algebra**

If your draw a sketch of this you will see that a right triangle can be formed. The base of the right triangle is 37 and the other leg is 23. The hypotenuse is the wire. Using the Pythagorean theorem, c^2 = 23^2 + 37^2 Solve for c

**Math**

The mode of a set of data is the value in the set that occurs most often. 3, 7, 9, 13, 18, 18, 24 In this set of numbers, the mode is 18, because 18 occurs the most times.

**Math7**

From 19C to -3C is 22 degrees difference

**Math7**

x = number of cookies x - (1/2 x + 3 + 2) = 7 x - (1/2 x + 5) = 7 2/2 x - 1/2 x - 5 = 7 1/2 x - 5 = 7 1/2 x = 12 multiply both side by 2 x = 24

**Algebra 1**

3y + 9 = 9 + 3y Commutative Property For addition, the rule is a + b = b + a in numbers, this means 2 + 3 = 3 + 2

**Geometry**

Is DB a line segment? Like this? D------E------B DE + EB = DB Add DE + EB to find DB Are you missing any info from this problem?

**Math**

1/7 + 1/-7 = 1/7 - 1/7 1/7 - 1/7 = ?

**Algebra**

C = number of campers Number of tents = C/3 + 1 T = C/3 + 1

**math**

Forgot to add the reasoning for setting the equation equal to 0. Since S(t) is the salvage value, to find how many years it will take for the saw to depreciate, you would set the equation to 0. This is because savage value would equal 0 dollars when an item was fully depreciated.

**math**

S(t) = -75t + 375 -75t + 375 = 0 -75t = -375 t = 5 years

**math**

D = RT (Distance = Rate x Time) R = rate of bike 0.67 = time of bike (2/3 = 0.67) 0.67R = distance of bike R + 12 = rate of car 0.33 = time of ca (1/3 = 0.33) .33(R + 12) = distance of car Since distance is equal 0.67R = 0.33(R + 12) Solve for R, rate of bike

**math (algebra)**

y + x + 4 = 0 x = 1/3 y Substitute x = 1/3 y in, y + x + 4 = 0 y + 1/3 y + 4 = 0 Multiply both sides by 3 3y + y + 12 = 0 4y = -12 y = -3 Check my math

**problem solving**

D = RT (Distance = Rate x Times D = 53.7 * 2.1 D = ?

**REPORT CARD QUESTION**

What are the requirements for first class honors?

**English 3**

Did you read the book? I would start there.

**3rd grade math**

5 cards in 1 hour 25 cards in 5 hours 5/hour + 5/hour + 5/hour + 5/hour + 5/hour = 25 cards/5 hour I'm not sure what a 3rd grader is able to do as far as division or multiplication.

**Algebra 1**

h = 73 700w/h^2 < 25 700w/73^2 700w/5329 < 25 Multiply both sides by 5329 700w < 133,225 w < 190.32 w < 190

**Economics**

Tutors don't do your homework. What exactly do you not understand?

**geometry**

15x - 13 = 90 Solve for x

**algebra**

Budget 80,000---family loan 38,250---small business loan 118,250--Total budget 0.25(118,250) = Budget for rent and utilities 29,563---money spent for rent and utilities (0.25 of 118,250)

**Algebra 1**

If this is the formula (Note h^2 means 'h squared' and use of parentheses) w = 166, h = 73 I = 700w/(h^2) I = 700(166)/(73^2) I = 116,200/5329 I = 21.81

**math**

Volume of a rectangular solid V = Lwh L = 4 m, w = 1.7 m, h = 54 cm = .54 m (100/54) V = 4(1.7)(.54) V = 3.672 m^3

**Calc**

I hit post, just as I realized what you meant. Sorry. Since the parentheses are around the (x), you most likely mean, y = (cubert(x)) + 2.

**Calc**

You need parentheses. Is your problem, y = (cubert(x)) + 2 y = (cubert(x + 2))

**math**

I'm not sure what a vertical math sentence is. Walked on Tuesday----0.25 Walked on Wednesday--1.60 Total walked---------1.85

**math**

Two Angles are Complementary if they add up to 90 degrees. V = angle V 2V - 3 = angle U V + 2V - 3 = 90 3V = 93 V = 31 angle V = 31 angle U = 59

**Math-Equations**

I am sorry. This exact problem has been posted at least 3 times in two days. Here are the equations. These are not easy to solve simultaneously. I used an online calculator for the answer if you need to check your answer. 25x + 35y +54z = 8277 x + y +z = 236 x + -y -z = 0 (in ...

**Math-Equations**

Please check your original post for an answer before reposting. This question has been answered. You were given the equations. Now, it is up to you to solve these equations simultaneously. If you post your answer I will check for correctness.

**math**

Ending Inventory------127,020 Beginning Inventory---105,850 Diff. = Turnover-------21,170 Sold Net Sales-------------423,400 Divided by Units sold--21,170 Per Unit Cost--------------20 I don't know if this is what you need.

**art**

15 marbles into 3 groups 15/3 = 5 3 groups of 5 marbles in each group

**Calculus**

I used r = 2/3 instead of r = 2/3 h! Thanks so much REINY. I really appreciate you taking the time to explain this to me. I am teaching myself calculus, and sometimes the book just doesn't explain things well. The r = 3h/4.5 threw me at first, until I figured out what she ...

**Calculus**

I think you have a mistake. I was working on this problem at the same time. V = 1/3 pi r^2 h Only 'r' is squared. It appears that you squared 'h' too. V = 1/3(pie) (3/4.5h)^2 Anyway, even with squaring h too, I don't come up with 9/64 pi.

**math**

You can leave the same and then subtract the equations. I like to have one equation as addition (+)variables and one equation with negative variables. Then I can add the equation. I know that I am less apt to make a mistake when adding equations as opposed to subtracting ...

**math**

5(7x + 3y = -1.5) = 35x + 15y = -7.5 3(2x - 5y = -30.3) = 6x - 15y = -90.9 35x + 15y = -7.5 6x - 15y = -90.9 Add two equations 41x + 0 = -98.4 41x = -98.4 x = -2.4 7x + 3y = -1.5 x = -2.4 7(-2.4) + 3y = -1.5 -16.8 + 3y = -1.5 3y = 15.3 y = 5.1 x = -2.4, y = 5.1

**math**

Multiply 1st equation by 5, and the 2nd equation by 3. Then add the two equations. This will eliminate the y variable. Take the value you get for x and substitute that value in either equation and solve for y.

**Math**

X = 2 + (1/x) Multiply both sides by x Xx = 2x + 1 Divide both sides by X x = (2x + 1)/X Now, you do the other problem. It's done the same way.

**Calculus**

x = distance of man from base of light y = length of shadow y/(y+x) = 6/18 Solve for y 18y = 6(y + x) 18y = 6y + 6x 12y = 6x y = 6/12 x = 1/2 x Find dy/dx of 1/2 x dy/dx = 1/2 Find derivative with respect to t dy/dt = 1/2 dx/dt x is increasing 3 ft/sec dx/dt = 3 ft/sec dy/dt...

**math**

40 kilometers = 24.8 miles 40 meters = 131.23 feet 4 meters = 13.12 feet 40 cm = 1.31 feet Can you answer now?

**Math**

After 6 yrs, the house decreased. The gains do not offset the losses. After three years the price is down 30% to start with, so the 10% increases are on calculated on a lower value. Do an example. On $50,000, after 6 years the house is down in value approx. 3%.

**maths**

Diameter d = 20 cm Circumference C = pi * d C = 3.14 * 20 = 62.8 cm in one revolution 62.8 cm 100 cm = 1m 62.8/100 = 0.628 m 0.628 m in one revolution 1 km = 1000 m 1000/0.628 = 1592.36 revolutions

**New Age Math**

The two equations, based on your fill-in-the-blanks above are, 25x + 35y + 54z = 8277 x + y + z = 236 Are you sure this is the exact problem as written? Are far as I know, this problem cannot be solved to get an exact number for x, y and z . To solve simultaneous equations in ...

**math**

Triangle ABC AB = x BC = x - 4 AC = 10 angle BAC = 60 deg Using Law of Cosines a^2 = b^2 + c^2 - 2bc cos A (x -4)^2 = 10^2 + x^2 - 2(10)(x)cos 60 x^2 - 8x + 16 = 100 + x^2 - 20x (0.5) x^2 - 8x + 16 = 100 + x^2 - 10x 2x = 84 x = 42

**geometry**

A = 1/2 bh h = altitude h + 4 = base 16 = 1/2 (h + 4)h Solve for h

**math**

Is this your problem? log 10 (1.4 * 10^(-5))