# Posts by steve

Total # Posts: 54,348

Algebra
(1+.08/4)^(4t) = 2 t = 8.75 years

Math
think about it. If x is replaced by -x then things flip horizontally. That is, across the y-axis. and yes, up 14

Math
correct. The radius has no effect on translation.

Mathematics
C = 3.00 + 10d now just use your numbers as needed.

physics2 lab
depends on the dimensions of the glass.

Math
Connor is 3 times as old as Erin. If her age is x, then we have (x-3) + (3x-3) = 38

Math
If the selling price was p, then to make a profit of 1 rupee per egg (of the original 30 dozen), we need (30*12-30)p = 1800 + 1(30*12) p = 6.55

Algebra I
recall that the line with slope m through (h,k) is y-k = m(x-h) Now just plug in your numbers.

Math
you can play around with Z table stuff at http://davidmlane.com/hyperstat/z_table.html

CAlculuss
Recall that the parabola y^2 = 4px has vertex at (0,0) and the distance from focus to directrix is 2p. Your parabola's distance from focus to directrix is 4, so p=2. The focus is at (3,5), so the vertex halfway between the focus and directrix, at (1,5). So, your parabola ...

geometry
I haven't seen the figure, but if the two areas are divided by the axis of symmetry, then yes, they are equal.

Maths
since volume is a function of r^3, the radius will be 1/10 of the original (since 1000 = 10^3) not sure what the css is, but maybe the above will help.

Chemistry
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Chemistry
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Chemistry
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math
if you let u=2^x, you have u^2-5u+4 = 0 u = 1 or 4 2^x = 1 ==> x=0 2^x = 4 ==> x=2

Algebra HELP
it is a rational expression a rational expression is the ratio of two quantities -- a fraction

Math
just multiply your 1988 population by 1.60694 why do you think they gave you that number?

Math
taxing each item is the same as adding them up and taxing the sum: (\$2.50+\$8.75+\$3.00+\$10.25)*.06

math
#1 is with: multiply the sum #2 is without: sum the multiples

math
well, the plans charge A: 8 + 3n B: 5n so, what's next?

math
she spent (1/4) + (1/3 * 3/4) + (2/5 * 1/2) = 19/30 so, 11/30 x = 5000

Maths
well, d/dx sinx = cosx d/dx cosx = -sinx so just crank 'em out

Calculus
4x^2 +y^2 = 48 + 2xy 8x + 2yy' = 2y + 2xy' y'(2y-2x) = 2y-8x ...

Calculus
recall that f is increasing where f' > 0 f' = 2cosx and you know that cosx is positive in QI and QIV. That is in (0,?/2) and (3?/2,2?).

Math/calculus HELPPP
so, if those points do not work, why are you mentioning them? Surely you can find the intersections of two lines ... ?? Got some work to show? There are 6 pairs of lines, but two of them intersect outside the shaded region.

Math/calculus HELPPP
hh? If you have the graphs, just mark where the lines intersect. I assume your graph looked kind of like this: http://www.wolframalpha.com/input/?i=plot+y-2x%E2%89%A5-3,+y%2B3%3E%E2%88%92x,+3y%E2%88%922%E2%80%8Bx%E2%89%A412,+2y%2Bx%3C8 Now, the lowest vertex is the ...

physics
calculate the loss in PE (mgh). That has been turned into KE (1/2 mv^2).

math!!
2/3 = 1.2/x x = 1.2 * 3/2 x = 6/5 * 3/2 = 18/10 = 1.8 use parentheses. You wrote 4/5 = (8/x) + 2 4/5 = 8/(x + 2) x+2 = 8 * 5/4 = 10 x = 8 cookies is correct

precalc
Assuming you meant y= -2cos(pi/6 x) + 8 then the center line is at y=8 and the amplitude is 2 so, what do you think?

thank you

James owes \$6,927 on a credit card with a 19.5% interest rate. What is the monthly payment he should make to pay off this debt in 12 months, assuming he does not charge any more purchases with the card? a-\$1531.34 b- \$577.25 c-\$124.82 d- \$640.02 My answer is D

The table summarizes the credit card debt Michael currently holds. Use this table to answer the question that follows. Credit Card Balance APR Minimum Payment Total Interest Paid Number of Months to Pay off Home Improvement Card \$2,500 23.4% \$100 \$2,095 125 Wear-It-Right Card...

math
n is the father of 3n-1,3n,3n+1 so, divide 2017 by 3 and check the remainder...

math
well, duh F is °Fahrenheit C is °Celsius

Math, Trig
y(0) = 0 and the vertex is at x=18 (halfway to the other root) and the parabola opens downward, so y = ax(36-x) the vertex is at (18,12) so 18a*(18) = 12 x = 12/18^2 = 2/3*18 = 2/54 y = 2/54 x(36-x)

Math
it is clearly 3:16 care to rephrase the question?

math
well, just list the possible outcomes: 1+1=2 1+4=5 1+9=10 ... 16+36=52 25+36=61 36+36=72 how many outcomes? how many set elements? divide

College Algebra
that is 8 years away, so 20700*1.09^8

College Algebra
all exponentials look the same. They all go through (0,1) b^x goes through (1,b)

Physics
(0.50*9.8N)/3cm = 1.63 N/cm ...

math
A = P(1+r)^t plug in your numbers

math
you have y^3 - 3^3 remember how to factor the difference of cubes? a^3-b^3 = (a-b)(a^2+ab+b^2)

Math
Surely you can count angles. How many do you see? (Curves do not count as angles.)

physics
I agree. I used the law of cosines.

m.p.bord maths subject
Not sure what you mean, but I'll guess Ax+By = a-b Bx-Ay = a+b ABX+B^2y = B(a-b) ABX-A^2y = A(a+b) (B^2-A^2)y = B(a-b)-A(a+b) y = (B(a-b)-A(a+b))/(B^2-A^2) Now you can find x. If that's not what you had in mind, you'd better explain it a bit better.

Math
Review your basic trig functions. You will see that the height h can be found using (h-6)/70 = tan 24°

harmonic progression
a useful sum to know is n ?(2k-1)^3 = n^2(2n^2-1) k=1

Physics
Looks right to me.

Physics
did you remember to use °K ? Show what you did, eh?

Physics
1m^3 * 10^6cm^3/m^3 * 8.96g/cm^3 * 1atom/(1.1*10^-22 g) = ? atoms the molar mass does not come into play

geometric progression
since sum(k=0..n) 2^k = 2^n - 1 your series is 1 + 3 + 7 + 15 + ... = (2-1)+(4-1)+(8-1)+... = sum(k=1..n) 2^k - n see where that takes you

Astronomy
B affects the view at different times during the year. Better think again; look at the words "every night"

English
thank you

English
"Know now then thyself, presume not God to scan;/The proper study of mankind is man." Which of these is nearest in meaning to the word presume, as it is used in the passage above? - hasten - invent - cease - attempt My answer is hasten but I thought about attempt

math
Nope. There are 4 variables. Knowing only two make it impossible to pin down the other two.

algebra
are you kidding? It will have to be at least the \$820 you started with, right?

Math can someone help
Where did you get the 0? With the sets A and C you just gave, AUC = {1,2,3,5,7,10} A?C = {2,5,7,10} Note that AUC = A and A?C = C because C is a subset of A You won't get any 0 elements unless you start working with B.

Math can someone help
A?C is the intersection of A and C. That is, all the elements which appear in both A and C. So, what do you think?

math
(12k^-2 (k^-3)^-4)/(6k^5) = (12k^-2 * k^12)/(6k^5) = (12k^10)/(6k^5) = 12/6 * k^10/k^5 = 2k^5 What do you get for the other one?

Algebra
If there are x spots now, then .40x = 24 x = 60 So, there will be 84 after completion.

g.p
If r = 2, Sn = a*(2^(n-1)-1) so, if b = a, it could be a gp a,2a,4a,8a,...2^(n-1)*a Sn = a(1+2+...+2^(n-1)) = a(2^n-1) = a*2^n-a

Chemistry
well, 2.1*10^24 molecules = (2.1*10^24)/(6.02*10^23) = 3.488 moles of O2 4/7 that many moles of NH3 are needed multiply that by the molar mass of NH3.

Physics
so, it took 3 seconds to go up, and 3 to come down. So, with initial velocity v, v-10*3 = 0 v = 30 h = 30t-5t^2 Now plug in t=3

English
"The number of souls in Ireland being usually reckoned one million and a half, of these I calculate there may be about two hundred thousand couples whose wives are breeders, from which number I subtract thirty thousand couples, who are able to maintain their own children...

English
Thank you

English
Read this excerpt from Alexander Pope's The Rape of Lock "No common weapons in their hands are found/ Like gods they fight l, nor dead a mortal wound.../ See, fierce Belinda on the Baron flies/ With more than usual lightning in her eyes..." This account of the ...

Chemistry
note that each molecule (or mole) of O2 produces two molecules (or moles) of H2O

Chemistry
Balance the equation: 2H2+O2 = 2H2O So, you have half as many moles of O2 as of H2 So, 1/2 the volume.

Physics
just plug in your numbers for the formula for a trajectory. The height y = 1.2 + (tan26°)x - 4.9/(40.4 cos26°)^2 x^2 is y(127) >= 3.5?

math
3.25 * (5 5/6) = 13/4 * 35/6 = 455/24 = \$18.96

English
correct (all the others are not even verbs)

pre calculus- math
e^.12t = 3

Algebra I
Huh? There's nothing to solve. Just evaluate the numbers... ½ (900kg)*(20m/s)^2 = ½(900)(20)^2(kg)(m/s)^2 = (450*400) kg-m^2/s^2 = 180000 N-m = 180KJ

Chemistry
Since the force is the same, the height will be inversely proportional to the densities (because the cross-section has the same area) -- think about it: half as dense (half as much mass), twice as high. So, if H is the height of mercury, the height h of iodide obeys h = (13.6/...

math
Looks like 3 to me: HHHHHTTTTT HHHHHHHHTT HHHHHHTTHT HHHHHHHHHH

Math
no idea. what does R have to do with u and r? Is R=r' ? If so, then #1: R = r' = u-r = {2,4,6,...} #2 u-r = {...-4,-2,0,2,4,...}

Algebra 2
huh? Does no one see that "ln" there? ln(x-4) < 6 since e^x is increasing, a<b ==> e^a < e^b x-4 < e^6 x < 4+e^6

Math
You want to get the variable all by itself. So, if you have 2x, you want to divide by 2, since 2/2 = 1, and that leaves you with 1x, or just x. -13x=-65 x = -65/-13 x = 5 multiply by 7, since 7/7=1 r/7=-8 r = -8*7 r = -56 add 10, so b is left alone: b-10=-14 b = -14+10 b = -4 ...

Math
so try posting a few problems you can't solve. Also, google is your friend. Looks for examples of your key topics.

Math - eh?
If this is reverse Polish notation, there are too many operators...

Math
since x = y+9, you want the maximum value of (y+9)y^2 = y^3+9y^2 Not sure what tools you have for finding the maximum, but a quick derivative will show that it is at x = 3 y = -6

Math
just multiply the coordinates by the scale factor!

Math 7a
3a - 4 <= 5 3a <= 9 a <= 3 do the same steps you use to solve an equation

Math 7a
wow - what a lot of text and bad formatting and non-standard font use! n/-3 + 5 > 4 n/-3 > -1 n < 3

Math
draw a dashed line at y=2 shade the region above it

math
4/15 + x + 3/5 = 1 4/15 + x + 9/14 = 15/15 ...

Human Kindness
You cannot. You can only encourage them.

5h - 9 = -16 + 6h subtract 5h from both sides add 16 to both sides now what do you get?

Math
perfect vision!

Math - eh?
you have mismatched brackets what are the spaces supposed to mean? "2f 3 -14 3" makes no sense and there's no "=" sign to make an equation. Geez - check what you write, willya?

physics
PV=kT, so you want (1.02*10^5)(.00661^3) = P(.00650^3) P = 1.07*10^5

Math
so, start with the smallest 3 primes: 2*3*5=30 So, any multiple of 30 can be divided by those three primes. Try using other primes, and see what you think ...

Math
recall the properties of multiplication (-w)(-10w^3) = (-w)(-10)(w^3) = (-1)(w)(-10)(w^3) = (-1)(-10)(w)(w^3) = 10w^4

Calculus
the slope of 3f^2 is 6f f' = 6*5*7=210 So far, so good. 3f^2(3) = 3*5^2 = 75 So, you want the line through (3,75) with slope=210 y-75 = 210(x-3) your surmise is correct

Math
L = F/2 - 5 F = 2(L+5) L + 2(L+5) = 79 Lindsey is 23 and her father is 56

math
2/3 < x/5 < 6/7 10/3 < x < 30/7 3.3 < x < 4.3 Looks like x=4

math
y=m is a horizontal line x=n is a vertical line y=x is a sloping line (a) perpendicular (b) neither

MATH
|x+3| ... shift left 3 -|x+3| ... reflect over x-axis -|x+3|-2 ... shift down 2