# Posts by steve

Total # Posts: 54,320

**Maths**

the length x of the hill is found via 30/x = sin35° you can take it from there, right?

**Math**

The length of the road is the perimeter of the field. So the cost to plant it is perimeter*cost/meter: 2(45+35)*15 Of course, that is the length of the inside of the road. If the trees are planed more toward the outside, then the length will be greater...

**math**

y^-4 = 1/y^4

**Computer**

nope

**Math**

-1/2 - 3/4 = -6/12 - 9/12 = -15/12 = -4/3 So, you have a typo. -1/2 + 3/4 = 3/12 = 1/4 Using 1/2 and 3/4 you cannot get any of the choices.

**Math**

correct. As is -2^4 = -16

**Math**

(x)^3 is exactly the same as x^3 (-2)^3 = (-2)(-2)(-2) = -8 -2^3 = -(2)^3 = -(2*2*2) = -8 works ok for odd powers, but not for even ones.

**Math**

the area of the path is the total area minus just the pool. Since the path is 2m wide, the radius of the whole is 22m. So the area of just the path is ?(22^2-20^2) = 84? m^2

**Math**

g(f) = (f^2+2)/f = ((?x+3)^2+2)/?(x+3) = (x+5)/?(x+3)

**Math**

the axis of symmetry is the line x=5 So, any domain on one side of that line will be one-to-one. Now, for the inverse, swap variables and solve for f^-1 x = (f-5)^2+2 x-2 = (f-5)^2 f-5 = ±?(x-2) f = 5±?(x-2) Now, we need one branch only, but ?(x-2) is only ...

**Algebra**

y = 15250 * 0.925^x

**Math**

I see spelling is also definitely on the list of troubles. :-)

**Math**

Nope. Try A. You need both addition and multiplication. Better review the topic 6.48 = 6 + 0.4 + 0.08

**algebra 2 - minimum or maximum**

recall that the vertex of the parabola ax^2+bx+c is at x = -b/2a So, your maximum is at x = 4/.5 = 8 now just find f(8)

**math**

The digit in the ten thousands place is greater than 7 9xxxx The sum of all five digit is 18.The greatest digit is equal to the sum of the other four digits. 94320

**Algebra 1**

It could also be written as -8n+5v 5v-8n

**physics**

recall that s = vt + 1/2 at^2 The total distance is thus .98*9.3 + .98*1.8 - 0.11/2 * 1.8^2

**advanced algebra 2**

euros = dollars * 6/5

**math**

100

**Math**

they are the basic trig functions (and that's tangent, not tangine)

**Geometry**

Hmmm. I think you also need a compass, if you don't trust the protractor.

**math**

the 100th, since LCM(20,50) = 100

**Math**

S/M = 2/11 Now just find M for the various values of S.

**beginning algebra**

2c*3d = 6cd there are 25 cents in each quarter, so in q quarters, there are 25q cents 0.25q is the number of dollars in q quarters.

**Math**

-3 * (-1 7/12) - (-3/2)^2 = -3*(-19/12)-(9/4) = 19/4 - 9/4 = 10/4 = 5/2

**Math**

7077 = 360*19 + 237 ...

**algrebra hellllllllp!!!!!!!!!!!!!! me plzzzzz**

you could always try using math symbols instead of words, as a start. It appears you mean -12/3*(-8+(-4)^2-6)+2 Inside each group of parentheses, do powers, then multiply/divide, then add/subtract. So, step by step we get -12/3*(-8+(-4)^2-6)+2 -12/3*(-8+16-6)+2 -12/3*(8-6)+2 -...

**Chemistry**

157km * 1mi/1.61km * 1gal/28mi * 3.785L/gal = 13.18L

**chemistry**

59.0 mL of a 1.60 M solution is diluted to a total volume of 268 mL The volume is increased by a factor of 268/59. So, the concentration is reduced by that factor. 59/268 * 1.60 = 0.3522M Now the volume is increased by a factor of 307/134, so the concentration is reduced by ...

**Math**

(x-43)(x+42)

**COLLED**

go look at such a machine. What do you see?

**computer application**

for i = 100 to 0 step -2 ; print i; assuming you don't want to go on forever with the negative ones ...

**Math**

You have 4 equations in 4 unknowns, so use elimination or substitution. For example, a+0+h+m = 72 a+c+h+0 = 80 0+c+h+m = 61 a+c+0+m = 57 subtract #1 from #2 and #4 a+0+h+m = 72 0+c+0-m = 8 0+c+h+m = 61 0+c-h+0 = -15 subtract #2 from #3 and #4 a+0+h+m = 72 0+c+0-m = 8 0+0+h+2m...

**College Algebra**

C(x) = 9000 + 1.20x R(x) = 3.00x now just find x where C=R

**College Algebra**

Just write the info in math. If $x is invested at 6%, then .09*3x + .06x = 1980

**Math**

If there are $x at 7% then the rest (14000-x) is at 11%. So, adding up the interest, you have .07x + .11(14000-x) = 1220

**College Algebra**

If there are x gallons of 13%, then the rest (40-x) is 23%. So, adding up all the disinfectant, you have .13x + .23(40-x) = .20*40

**Math**

see related questions below, or the mixture problems posted after this one.

**Math**

see the related questions below, or the mixture problems posted after this one.

**Math**

just add up the values of the coins. If there are d dimes, then 5(d+5) + 10d = 115

**Math**

see related questions below, or the coin problems posted after this one.

**Algebra**

see related questions below, or the mixture problems posted after this one.

**mr hunt wishe to enclose his goat in a wire fence**

so, is 3*7.9 + 4.075 <= 25 ?? Hint 21+4 = 25

**Trig**

Assuming that Mack is looking at Joey's feet, draw a diagram. It should be clear that if the tree's height is h, then h/25 = tan 53°51" Now just get out your calculator...

**Pre Calculus**

Recall that Matrix multiplication is always commutative if ... ... one matrix is the Identity matrix. ... one matrix is the Zero matrix. ... both matrices are 2×2 rotation matrices. (basically case #2) ... both matrices are Diagonal matrices.

**Math**

multiply/divide before add/subtract. So, you really have (55÷11)+7*(2+14)

**Pre Calculus**

can you skip the LaTex? It appears that you are saying that w = (2,1) and there is a 2x2 P such that w•v = Pv or something like that. Correct?

**Pre Calculus**

If MA = I, then A = M-1 Can you do matrix inverses?

**Algebra**

If x kg are added, then we have .55*160 + 1.00x = .70(160+x)

**PreCalculus**

(f-g)(x) is just f(x)-g(x). That is easy enough: f(x)-g(x) = (x^2+3x-1)-(x^3+4x^2+1) = -x^3 - 3x^2 ...

**Maths**

each cm is 0.01 meters, so you have 17m + .80m = 17.80m

**math**

if their ages today are a and b, then we have a = b+9 a-5 = 1.5(b-5) b+9-5 = 1.5b - 7.5 11.5 = .5b b = 23 so, a=b+9=32 (a+4)+(b+4) = 36+27 = 63

**math**

If the amounts invested are a and b, we are told that 1200(1.20)^2 = b(1+.15*3) + 42 b = 1162.76 Now you ask what percent is B of "that". No idea what you mean, but if you want the percent of the total amount invested, that would be b/(a+b) = 1162.76/2362.76 = .4921...

**Calculus**

I get it!

**Math**

just use your usual distance formula. The final displacement is just 100*?(4^2+163^2) = 100?26585 = 16305m

**Math**

total distance is just the sum of all the separate pieces. I'm sure you can add them up. For the final location, just add up the separate displacements (in 100's of meters). (0,0) to (-23,0) to (-23,-175) to (-4,-175) to (-4,-163) Now you can figure the east-west, ...

**Math**

7*93 = ?

**Chemistry**

the net charge on any atom is zero. Only ions carry a net charge. one mole is 6.02 * 10^23 atoms. Each molecule of water (H2O) has two hydrogen atoms. each mole of H2O has a mass of 2*1 + 16 = 18 grams.

**maths**

2*2 = 4 cm^2 represents 5*5 = 25 km^2 so, you have 9/4 * 25 = 56.25 km^2

**physics**

v = vo + at s = vo*t + 1/2 at^2 vo + a*4.5 = 35 vo*4.5 + 1/2 a*4.5^2 = 100 so, (35-4.5a)(4.5) + 1/2 a * 4.5^2 = 100 a = 5.68 m/s^2

**physics**

I guess you want the total distance. Since v = at and s = vt + 1/2 at^2, s = (1/2)(1.4)(4.1)^2 + (4.1)(1.4)(1.8) + (1/2)(-1.8)(1.8)^2 = 19.18 m final velocity is v = 1.4*4.1 + (-1.8)*1.8 = 2.5 m/s average speed is 19.18m/(4.1+1.8)s = 3.25 m/s

**algebra**

t = 3m-8 g = m+5 m+t+g = 72 m + 3m-8 + m+5 = 72 5m-3 = 72 5m = 75 m = 15 Mark: 15 Tony: 37 Grant: 20 ------------ total: 72

**computer science**

I'd say C E might be considered, but the error in a double-precision value is out at the 14th significant figure, so I'd not consider that much of a loss of precision.

**math**

just solve both sides at once. -15<x-8<-4 add 8 everywhere: -15+8 < x-8+8 < -4+8 -7 < x < 4 what do you get for the others?

**Algebra**

Assuming the usual sloppiness with parentheses, I'll assume x=?(6x-27)+3 x-3 = ?(6x-27) x^2-6x+9 = 6x-27 x^2-12x+36 = 0 (x-6)^2 = 0 x = 6

**Math**

the whole lawn is 1/(3/5) = 5/3 as much as he can cut in 3/4 of an hour 5/3 * 3/4 = 5/4 or, keeping track of the units, (1 lawn) * (3/4 hr)/(3/5 lawn) = 3/4 * 5/3 = 5/4 hr

**Math**

however, if y*0.4 = 2 then y=5

**Math**

move the decimal point 5 places to the left: 0.0000356

**computer science**

Looks like B to me. Actually, it's good to 14 decimal significant figures, but 5.0 is good enough.

**Math**

If $x was invested at 5%, then the rest $(4100-x) was invested at 10% So, just add up the interest, and you have .05x + .10(4100-x) = 370 Now just find x ...

**Algebra**

Just use the distributive property: (x+3)(x^4-4x^2+5) = (x+3)(x^4) + (x+3)(-4x^2) + (x+3)(5) = x^5 + 3x^4 - 4x^3 - 12x^2 + 5x + 15

**Algebra help pls**

Nope. 7-(9x + 3) = 7-9x-3 = -9x+4

**Algebra help pls**

A: 3 = 4*1? Nope B: -4 = 4*(-1)? Yes C: -1 = 4(-4)? Nope D: -4 = 4*1? Nope

**Algebra**

#2 correct #3 correct

**Engineering Mechanic**

well, h(t) = 7.7t - 4.9t^2 max height is reached at t = -b/2a = 7.7/9.8 so plug that in to find h there.

**Math**

30=6*5=10*3, so 25/30, 9/30

**Math**

all correct.

**Math**

If b = -2, then since (-2)^2 = (-2)(-2) = +4 (-2)^3 = (-2)(-2)(-2) = -8 [-4b-8]+[-1-b^2]+2b^3 = [-4(-2)-8]+[-1-(-2)^2]+2(-2)^3 = [8-8]+[-1-4]+2(-8) = 0-5-16 = -21 9[9-8x] = 2x+3 81-72x = 2x+3 78 = 74x x = 78/74 = 39/37

**Math**

I agree

**message for Dr. BOB**

Dear Dr. Bob, I just wanted to thank you. You helped me graduate from college by helping me with with chemistry and now I am getting my master's degree. You have no idea what you have done for me. Again, THANK YOU!

**English**

thank you

**English**

With which of these statements does the crone in "The Wife of Bath’s Tale" save the life of the knight? • “A woman wants… sovereignty/Over her husband as over her lover…” • "It's little wonder if I twist and wallow!/God ...

**English**

thank you

**English**

What is the MOST likely reason that Chaucer presents The Canterbury Tales as a first-hand account? to establish that he actually did observe the events he describes to create a sense of immediacy and authenticity to prove that the characters in the work had actually told him ...

**English**

That's the site as well as reading the tale where I came up with the doctor.

**English**

from The Canterbury Tales: The Prologue With which of these Canterbury Tales characters does Chaucer illustrate a division between religious and scientific thought? the Narrator the Skipper the Doctor the Friar My answer is the doctor

**English**

Thank you

**English**

Which excerpt from “The Prologue” of The Canterbury Tales best indicates that the Nun is a compassionate person? (1 point) • “Her veil was gathered in a seemly way,/Her nose was elegant…” • “And well she sang a service, with a fine/...

**Algebra**

correct

**Science**

sorry. Neither one, if by "pure substance" you mean an element.

**Math**

m/6153 = 3/7

**Math**

so, what is the perimeter of the rectangle? The perimeter of a square is 4 times the side s. The area is s^2

**Math**

n+a < m+b

**Math**

those sure look like powers of 2 to me ...

**math**

n+3P6 = (n+3)(n+2)(n+1)(n)(n-1)(n-2) n+2P4 = (n+2)(n+1)(n)(n-1) (n+3)(n-2) = 14 n=4

**Math**

ummmm, 4^3, right?

**Math**

The mean is the total divided by how many there are. So, the new mean is (50*38-45-55)/48 = 37.5

**Math**

Remember the order of operations... 5^2x4+2^3 = 25x4+8 = 100+8 = 108

**maths**

If the fraction is n/d, we are told that d = 4n-1 Now we are told that (n+1)/(d+1) = 3/8 (n+1)/(4n-1+1) = 3/8 (n+1)/(4n) = 3/8 8(n+1) = 3(4n) 8n+8 = 12n 8 = 4n n = 2 The original fraction was 2/7 adding 1 top and bottom gives 3/8

**Math**

u = 1+?x ?x = u-1 du = 1/(2?x) dx = 1/(2u-2) dx so, dx = (2u-2) du ?1/(1+?x)^4 dx = ?1/u^4 (2u-2) du = 2?(1/u^3 - 1/u^4) du ...