Sunday
February 7, 2016

Posts by steve

Total # Posts: 37,440

math
geez, give it a rest already, willya? 10^3 * 26^2
January 28, 2016

geometry
clearly, when the longest side is the sum of the other two sides, the triangle has flattened into a line. So, 17-x = 8-x + 15-x 17-x = 23-2x x = 6 cutting off 6" leaves the lengths of 2,9,11, a flat triangle.
January 28, 2016

Math
Starting with $10, I bought 3 candy bars at 75 cents each, and 2 sodas at 50 cents each. How much money was left after the purchases?
January 28, 2016

Math
p=3s s=2m p-(x+y) = s+x p-(x+y) = m+y If p gives away 1/2 of his eggs, 1/6 to s and 1/3 to m, then Pablo has p/2 Sofia has p/3 + p/6 = p/2 Mia has p/6 + p/3 = p/2
January 28, 2016

Math Help
well, we are told that v(t) is the velocity at time t. Looks like B to me.
January 28, 2016

Help Math
exatamente correto de nada
January 28, 2016

math
37/1 -16/5 92/10 = 46/5 -23/100
January 28, 2016

Algebra
If there were x of each to start, then x = 4(x-66)
January 28, 2016

writing equations-Math
20(x-2) = 60 60/(x-2) = 20
January 28, 2016

triggggg help
well, tan = sin/cos, right? Also, 67.5° = 3pi/8 = tan(1/2 * 3pi/4) so you can use the half-angle formula tan(x/2) = sinx/(1+cosx) tan 3pi/8 = (1/√2)/(1-1/√2) = (1/√2) / (√2-1)/√2 = 1/(√2-1) = √2+1 or, √((2+√2)/(2-√...
January 28, 2016

Calculus
(√(6-x)-2)/(√(10-x)-3) (√(6-x)-2)(√(10-x)+3) ----------------------- (√(10-x)-3)(√(10-x)+3) (√(6-x)-2)(√(10-x)+3) ---------------------- 10-x-9 as x->1, that is (6√5 - 12)/±0 undefined
January 28, 2016

Tips
Once you have submitted your question, the screen will show a line like Your question, Tips, was successfully posted Click on the word Tips and your posting will open up again for your review. Proofread it and watch for typos, formatting, font problems, etc. Make sure it is ...
January 28, 2016

Tips
See tips below.
January 28, 2016

Calculus
http://www.jiskha.com/display.cgi?id=1453991598
January 28, 2016

Math
1/2 = 2^-1 32 = 2^5, so (2^-1)^(2-x) = (2^5)^(x+1) 2^(-1(2-x)) = 2^(5(x+1)) -2+x = 5x+5 4x = -7 x = -7/4
January 28, 2016

intermediate algebra
since time = distance/speed, 186/(24+x) = 102/(24-x)
January 28, 2016

Math
Draw a diagram. The line from the satellite and a city is tangent to the radius from the center of the earth. If that radius is r, then the angle θ subtended by the satellite and one city is θ = 1125/r So, if the satellite is h mi high, r/(r+h) = cosθ h = r/cos...
January 28, 2016

Math
sorry - ain't so. Check for typos However, cot(sec^-1(A)) = √(A^2-1) cot^2(sec^-1(A)) = A^2-1 I think I can see how the question was mangled. Can you?
January 28, 2016

math
take a look at the 2nd related question below.
January 28, 2016

Calculus
since p(t) is the population given time, p^-1(t) is the time needed to attain a certain population. p=7500/(1+749e^-0.15t) 1+749e^-0.15t = 7500/p 749e^-0.15t = 7500/p - 1 e^-0.15t = (7500/p - 1)/749 -0.15t = ln((7500/p - 1)/749) t = -20/3 ln((7500/p - 1)/749) or t = -20/3 ln((...
January 28, 2016

maths
(1) 1600*30 (2) 0 (3) p = mv, so dp/dt = m dv/dt = 1600*(0-30)/(20-0) = -2400 kg-m/s (4) see (3) (5) F = ma
January 28, 2016

math
start here, where the facts are written as algebra: x+y = 120 3x = 2y
January 28, 2016

mathematics
there are many good amortization calculators online.
January 28, 2016

analytic geometry
see related questions below
January 28, 2016

math
c = 5b c+2 = 3(b+2) c+2 = 3(c/5 + 2) c+2 = 3c/5 + 6 2c/5 = 4 c = 4*5/2 c = 10 Check: Carol is now 10, brother is 2 in two years, Carol is 12, brother is 4
January 28, 2016

math
Kleeneces
January 28, 2016

Math
No idea about Jean, but (3/5)/(1/9) = 27/5 or 5 2/5 as much
January 28, 2016

maths
well, start with s = rθ and then plug in your numbers θ is in radians, not degrees.
January 28, 2016

maths
since 8 mo. is 2/3 year, 2520(2/3)(r/100) = 84
January 28, 2016

Maths
since time = distance/speed, 40/x + 250/(x+20) = 3
January 28, 2016

calc
I think you must mean s(t) = e^(cos(t)) velocity is zero when v(t) = ds/dt = e^cos(t) (-sin(t)) = 0 sin(t)=0 when t is a multiple of pi. So, it looks like you are in error.
January 28, 2016

Math
I don't think you can answer the question without knowing how much the mirror had to be tilted. If the mirror is tilted an angle x, and the angle θ from the normal is formed by the ray from eye to mirror to window, then we have (if the height of the window is h): 1.82...
January 28, 2016

analytic geometry
the asymptotes are always y=±(b/a)x 2x^2 + 5y^2 - 16x + 20y + 108 =0 2x^2-16x + 5y^2+20y + 108 = 0 2(x^2-8x) + 5(y^2+4y) + 108 = 0 2(x^2-8x+16) + 5(y^2+4y+4) + 108 - 2(16) - 5(4) 2(x-4)^2 + 5(y+2)^2 + 56 = 0 I suspect a typo, since the above equation has no real ...
January 28, 2016

Math
you can multiply the 2nd equation by -5, and then you have 5x + 2y = 1 -5x + 15y = -35 Now you can easily add them to get rid of x, then find y.
January 28, 2016

Calc II
4sec(x) dy/dx = e^(y+sin(x)) 4secx dy = e^y e^sinx dx e^-y dy = 1/4 e^sinx cosx dx -e^-y = 1/4 e^sinx + c e^-y = -1/4 e^sinx + c -y = ln(c - e^sinx/4) y = -ln(c - e^sinx/4) y(0) = -5, so -5 = -ln(c - 1/4) 5 = ln(c - 1/4) e^5 = c - 1/4 c = 1/4 + e^5 y = -ln(1/4 + e^5 - e^sinx/4)
January 28, 2016

analytic geometry
y^2 = 4px has directrix x = -p focus x = p the l.r. has length 2p. No electricity is involved. the l.r. of an ellipse has length 2b^2/a recall that b^2+c^2 = a^2 and eccentricity is c/a
January 28, 2016

math
just set R(x) = C(x) and solve for x.
January 28, 2016

Math
well, you know y=10-6x so substitute that into the other equation.
January 28, 2016

operating system
LRU
January 28, 2016

Math
only two
January 27, 2016

analytic geometry
However, they wanted the acute angle. So, Sylvia, now it's up to you...
January 27, 2016

Math
(1/4 + 2/3)x + 200 = x
January 27, 2016

Riddle
man's mother's nephew is a cousin of the man cousins have the same grandparents. so, the woman's father is also the man's cousin. 2nd cousins share the same great-grandparents. So, the man and the woman are 2nd cousins, once removed.
January 27, 2016

AAMU
speed = distance/time, so (2+2)/(2/8 + 2/6) = 48/7 km/h
January 27, 2016

Math
what is the only symbol which has no definite value?
January 27, 2016

math
If you worked x hours, then sister worked 7-x hours. So, now you just have to solve 4x + 5(7-x) = 32 Plug and chug.
January 27, 2016

Math
5/3 g + 5/6 - g = 2/3 g + 5/6 or (4g+5)/6
January 27, 2016

Pre-calculus
We have a right triangle whose hypotenuse is the distance (d) between the boats: d^2 = 16t^2 + 18(t-1)^2
January 27, 2016

Pre-calculus
assuming the tank is pointed-end down, the water forms a cone, so v = π/3 r^2 h Now, using similar triangles, (r/h) = 9/16, so v = (π/3)(9/16 h)^2 h = 27π/256 h^3 h = 3/8 ∛(2πv) since this is precal, not calculus, I'm not sure what tools you have ...
January 27, 2016

Math
you are correct.
January 27, 2016

math
just add the differences to the average. Clearly the results will be in the same order as the differences.
January 27, 2016

math...finding cubic feet
well, v = πr^2 h so, plug in your numbers. Apparently the radius is 3/8 inches Then recall that it takes 1278 in^3 to make 1 ft^3.
January 27, 2016

Calc 1 limits
If you canceled out the x+3 terms, that leaves the x-3 terms, so your quotient is 1/(x-3)^2 But your answer is indeed 1/36
January 27, 2016

trigonometry
use the difference formula: sin(π-x) = sinπ cosx - cosπ sinx sinπ=0 and cosπ = -1, so you wind up with 0 - (-1)(sinx) = sinx Also, if you draw the angles in standard position, recall that sinθ = y/r cosθ = x/r since y is positive in QI and ...
January 26, 2016

Math
for the cone, the slant height s and the height h and the radius r obey s^2 = r^2+h^2 so, the height is √20=2√5 cone volume is 1/3 πr^2h = 32√5 π/3 cylinder volume is πr^2h = 102π so add them up
January 26, 2016

Math
the area of the base with diameter d is π/4 d^2 = π/4 * .5^2 = π/16 the volume is just base * height better review your formulas. Here's a good reference: http://www.regentsprep.org/regents/math/algebra/as2/solids.htm if you still have questions, or just ...
January 26, 2016

Math
no problem. Of course, telling me the front side has the line does not help, since I cannot see which face is the front.
January 26, 2016

Math
just plug the numbers into your volume formulas. The square-ish part cannot be a cube, since the sides differ in length. Must be a rectangular prism. You don't say which side has the diagonal line, but using the Pythagorean theorem to find h, if it is on the 1" side, ...
January 26, 2016

Calculus
Just keep in mind the chain rule. Every time you have a y, you will produce a y'. x^2 = (x-y)/(x+y) 2x = ((1-y')(x+y) - (x-y)(1+y'))/(x+y)^2 At this point, it's just algebra. Collect all the y' stuff on one side, and you wind up with (one form, anyway): y&#...
January 26, 2016

input output
Look at the first two terms. x increases by 8, and y increases by 12. So, clearly the rule is y=(3/2)x + ... Since (3/2)*4=6, and y=6, our rule must be just the above: y = 3/2 x So, when y=60, x=40 Fill in the blank with any convenient values: 20, 30 comes to mind.
January 26, 2016

Math
If the length is x, then 2(90+x) = 500
January 26, 2016

6th Grade Math
Note that (3/4)(4/3) = 1 That is, 1 hour is 4/3 as long as 3/4 hour. So, he can mow 4/3 as much: (2/3)(4/3) = 8/9 of the lawn.
January 26, 2016

perimeter and area
correct on both.
January 26, 2016

Science
use a third container. Pour lemonade from one glass into it and mark its height. Then do the same with the other glass. If the height is the same, the glasses contain the same volume of drink.
January 26, 2016

Algebra 1
#1 growth factor: 1.22 initial: 180 at 8pm: 180 * 1.22^8 Consider how I derived the math from the words, and work on the others. Let us know which items seem difficult.
January 26, 2016

Math
to what? clarify your question if you want a helpful answer.
January 26, 2016

math
try using a common denominator: 3/10, 4/10, ... , 6/10, 7/10 now it's easy, right? Tn = (n+2)/10
January 26, 2016

math
given only two terms, it is possible to make up a variety of ways to get from one to the other. However, since the two values are 3/10, 4/10 The easiest rule I can think of is just to add 1/10 to get the next term.
January 26, 2016

selma high
42
January 26, 2016

MATH HELP
the radius of the cone is the same as the radius of the cylinder. Then if you have the heights of the cylinder and cone, just use the normal volume formulas.
January 26, 2016

MATH
no. did you check to see that your answer works? q^2 = 4 since 32q^2 = 8*4*4 = 32*4
January 26, 2016

MATH
pq^2=k so, you want q such that 32q^2 = 8*4^2
January 26, 2016

math
forget the p. It is just a scale factor. using the law of cosines, 6^2 = 4^2 + 5^2 - 2*4*5*cosA A = 82.82° Now do a similar equation for B, and then C is easy, since A+B+C=180
January 26, 2016

math
since Lucy pays 30%, her share will increase by .30(650-450)
January 26, 2016

math
450 * 4π cm
January 26, 2016

Math
g^-1(x) = 16-4x f^-1(x) = x/4 - 1/16 (g∘f)^-1 = 63/16 - x (f^-1 ∘ g^-1)(x) = (16-4x)/4-1 = 63/16 - x It is not hard to show that (g∘f)^-1(x) = (f^−1∘g^-1)(x) works with matrices as well: (AB)^-1 = B^-1 A^-1
January 26, 2016

Calculus
Assuming you meant x instead of h, V = 1/3πx^2(18-x) = 6πx^2 - 1/3πx^3 dV/dx = 12πx - πx^2 the jar's volume is 400π cm^3. If it drains in π seconds, that's 400cm^3/s. That is dV/dt dV/dt = (12π - 2πx) dx/dt -400 = (12π-...
January 26, 2016

Marble hall
sure. why not?
January 26, 2016

Math
x/2 + 16 = 36
January 25, 2016

math
{a,b}∪{a,c} = {a,b,c} {a,c,d}∩{b,d,e} = {d} {abc}×{d} = {ad,bd,cd} In part b, since the two sets have no elements in common, the intersection is empty.
January 25, 2016

Calculus
1/y + 1/x = 1 + y^2 -1/y^2 y' - 1/x^2 = 2y y' (-1/y^2 - 2y)y' = 1/x^2 y' = (1/x^2)/(-1/y^2 - 2y) = -(1/x^2)/((1+2y^3)/y^2) = -y^2 / (x^2(1+2y^3)) -(x^2/y^2) -x^2 y^-2 -2x y^-2 + 2x^2y^-3 y' 2x(x-y)/y^3 y' no equation, but that's where we are so far.
January 25, 2016

College Algrebra
or, consider this a normal work problem: 1/60 + 1/66 = 1/t t = 220/7
January 25, 2016

Math
240/16 = 15 so, the rectangle is 15 tiles long. 60/15 = 4 so the rectangle is 4 tiles wide. Thus, it is 4*16 = 64 cm across
January 25, 2016

Math
4p/3 - 5
January 25, 2016

math
4:1 = 12:3 now you can tell which ratio is greater
January 25, 2016

Math
(1-7)/(18-(-2)) = -6/20
January 25, 2016

Algebra
The scale is 3ft/in, so the real-life dimensions are 15ft:6ft The area is thus (5in*2in)*(6ft/2in)^2 = 10*3^2 = 90 ft^2
January 25, 2016

Math
without actually doing a regression, check the average slope: (255-183)/(79-67) = 6 84-79=5, so 255+6*5 = 285 b is closest to that value.
January 25, 2016

Math
looks ok to me
January 25, 2016

Math
mark each pair on a number line. > means "to the right of" < means "to the left of"
January 25, 2016

math
seems simple enough to me 350/260 = 35/36 Now it's clear that the answer is 1 9/26 since 35=26+9
January 25, 2016

Math- Urgent, please help!
before posting the question and your answer, did you try actually using your number to see whether it worked in the equation?
January 25, 2016

Math
d + d+3 = 17
January 25, 2016

MATH HELP MS SUE OR SOMEONE
every line segment joining two points on a circle is a chord. So, every diameter is a chord. chords do not have to pass through the center.
January 25, 2016

Math
f◦g = 2^g = 2^(3-x) = (2^x)/8 g◦f = 3-f = 3-2^x the domain of all exponentials is all reals. The range of all a^x is (0,∞) see where that leads.
January 25, 2016

math
or, to keep in scientific notation, 5.14x10^6
January 25, 2016

Calc help!
put it all over a common denominator. How do you add 2/3 + 5/7 ? You use the common denominator of 3*7. Do this the same way.
January 25, 2016

Maths
that's vertices, not testices. The circumcenter lies at the intersection of the sides' perpendicular bisectors. So, to start, find the equations of two of the bisectors. AB: slope=1/3 midpoint is (7/2,7/2) pb: (y-7/2) = (-3)(x-7/2) AC: slope=4 midpoint is (5/2,5) pb: (...
January 25, 2016

maths
not unique, since 2^2 3^4 5^2 or 5^2 3^4 2^2 a+b = 2+3 = 5 or a+b = 5+3 = 8
January 25, 2016

math
9 + x <= 14 x <= 5
January 25, 2016

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