Tuesday
September 23, 2014

Posts by Steve


Total # Posts: 25,175

Fractions
(5 1/2) / (3/4) = 11/2 * 4/3 = 22/3 = 7 1/3 So, she has enough for 7 servings, with 1/3 serving left over. For 10 people, she needs to have only 11/2 * 1/10 = 11/20 cup per serving 10 servings of 3/4 cup each is 30/4 = 7 1/2 cups
September 23, 2014

math
If the numbers are relatively prime, then x(x-7) = 60 x^2 - 7x - 60 = 0 (x-12)(x+5) = 0 So, the numbers are 12 and 5
September 23, 2014

Math
To use the quadratic formula, you need to arrange things so that you have y = ax^2 + bx + c So, (x - 10 )(x + 9 ) = 2 x^2-x-90 = 2 x^2 - x - 92 = 0 Now just apply the formula.
September 23, 2014

math
(-a,b)
September 23, 2014

Math
x^2 + 4 x = 4 x^2 + 4x - 4 = 0 Now just apply the formula.
September 23, 2014

Maths
The cylinder has radius r The cone has radius 2r So, the ratio of volumes is (πr^2h)/(π(2r)^2h/3) = (πr^2h)/(4πr^2h/3) = 3/4
September 23, 2014

College Pre-Calculus
m(f) = f/5280
September 23, 2014

Math
27/3 + 5*2 = 19
September 22, 2014

math
1kg/(4.8g/cm^3) = 208.333 cm^3 So, now you know that 4π/3 r^3 = 208.333
September 22, 2014

Algebra1
either or both
September 22, 2014

physics
F = ma -1.50*10^4 = (1.96*10^4/9.81)(a)
September 22, 2014

math
same as what?
September 22, 2014

Math
77 = 11*7, so (6+5)*(9-2)
September 22, 2014

algebra
Just work it step by step: 105/(-20+15) ------------------- 45/(-9)+12 105/(-5) ------------ -5+12 -21 --------- 7 -3
September 22, 2014

Math
r(x) = (600-4x)(250+4x) Now plug and chug.
September 22, 2014

Algebra
If x lbs at $7, then 7x + 5(50-x) = 5.79(50)
September 22, 2014

math
what difference does it make how far the sun is from earth? Unless the distance to Mars is measured in a.u.
September 22, 2014

Advance Algebra
v(x) = x(12-2x)(10-2x) Since the sides must have positive length, we need 10-2x > 0, or x<5 Since the cuts must also have nonzero length, x>0, so the domain is 0 < x < 5
September 22, 2014

math
After t minutes, the positions are (if P=(0,0)) turtle: (0,4t) snail: (50,-2t) So, the distance d can be found from d^2 = 50^2 + (6t)^2
September 22, 2014

Algebra 2
just expand as you normally would a polynomial, and you get 30i^3 + 125i^2 + 120i But, once you recall that i^2 = -1 i^3 = -i, you have -125 + 90i
September 22, 2014

Geometry
Hard to parse the garbled sentence, but if the hill slopes at a 30 degree angle, then the tree makes angles of 60 and 120 with the hill. To explain, just draw a diagram and label all the angles.
September 22, 2014

algebra 2
First, that's equal to, NOT too! It's a lot easier just to write x >= 2. With that said, let's proceed. #1: ok #2: ok #3: Hmmm. This one is no harder than the first two, just a bit longer. 4(1-3n)-14>4(2n+3)-9n 4-12n-14 > 8n+12-9n -12n-10 > -n+12 -11n &...
September 22, 2014

trigonometry
A wheel with a 15-inch diameter is turning at the rate of 60 revolutions per minute. To the nearest inch per minute, what is the linear speed of a point on the rim?
September 22, 2014

Maths
start factoring: 2*2198 4*1099 4*7*157 = 28*157 What's with "using the numbers 1-9"? Seems like a stupid condition.
September 22, 2014

Math
(b) no angles provided
September 22, 2014

algebra
clearly, when 50.00 + 3.50x = 75.00 + 2.25x Now just solve for x.
September 22, 2014

algebra
5n+10d+25q = 325 n = d+2 q = n+1 Now just start substituting in to solve for the variables.
September 22, 2014

Math
What's the trouble? Just start writing the words as equations. We are told: a+b+c = 18 a = 2(c-b) (because c > b) b = (a+c)/2 Now just go through the usual procedures to solve several equations.
September 22, 2014

Math
correction on #1. What I gave was the solution for a particular radius. Since we have to consider all possible such circles, the locus is the perpendicular bisector of the line joining centers of the circles. All points on that line are equidistant from the two centers.
September 22, 2014

Math
since |z-c|=r is a circle of radius r, |z+1| = |z+i| is the intersection of two circles. If z = x+yi, Re z = x |z-1|^2 = (x-1)^2 + y^2 So, you need x^2 = (x-1)^2
September 22, 2014

math
If there are x,y,z of each cost, we have x+y+z = 20 4.00x + 0.25y + 0.50z = 20.00 Since we have only two equations, there are multiple solutions. Let's work with knowing x. Then we have y = 14x-40 z = 60-15x Since y and z must be positive, we need x >= 3 and x < 4. ...
September 22, 2014

math
(150*15)/500 = 4.5 so, now you can figure it out, right?
September 22, 2014

Math Help Please
just solve 16t^2 = 1614
September 22, 2014

Math
how are the 6 fields to be arranged? 2x3: 9x+8y = 1200 a = 6xy = 6x(1200-9x)/8 max area at x = 200/3 1x6: 12x+7y = 1200 a = 6xy = 6x(1200-12x)/7 max area at x = 50 Note that the fencing is divided equally among lengths and widths.
September 22, 2014

math
Ben takes time t = (d/2)/r + (d/2)/w = d/(2(r+w)) Bob covers distance w(t/2) + r(t/2) = d so Bob's time is 2d/(r+w) So, which time is less?
September 22, 2014

Algebra
9-c < 2 c > 7 -3c > 15 c < -5 so, c < -5 or c > 7 See http://www.wolframalpha.com/input/?i=solve+9+-+c+%3C2+or+-3c+%3E+15+
September 22, 2014

Precal
sec θ = r/x = √218/-7
September 22, 2014

Math
3^2-12/(6-3)*8 9-12/3*8 9-4*8 9-32 -23
September 21, 2014

Math - Madison the Mooch
The equation describes an ellipse. There is no inverse, because each value of x corresponds to 2 values of y (the vertical line test). There is no such thing as an inverse equation. If you want to find x as a function of y, then 2x^2 = 4 - 3y^2 x^2 = (4-3y^2)/2 Now, there is a...
September 21, 2014

Math
False even without doing the math, the left side is odd and the right side is even.
September 21, 2014

AP Calc. AB
correct.
September 21, 2014

algebra
(2,10,5)
September 21, 2014

Math
(6-6)/(6x6+6)=0
September 21, 2014

Algebra
as usual, first just clear fractions: (n+9)(7) = 6(d+9) (n-7)(3) = 2(d-7) 7n+63 = 6d+54 3n-21 = 2d-14 7n-6d = -9 3n-2d = 7 Now can you solve for n and d?
September 21, 2014

Algebra
Just put the words into symbols. If the original fraction is n/d, then (n+9)/(d+9) = 6/7 (n-7)/(d-7) = 2/3 Now just solve for n and d.
September 21, 2014

math
If the base of the rectangle has length 2x, and height y, the area is a = 2xy = 2x√(1-x^2/16)(4) = 2x√(16-x^2) da/dx = 4(8-x^2)/√(16-x^2) so, max area occurs at x=√8, and the rectangle is 2√8 by √2
September 21, 2014

AP Calc. AB
Clearly A is not continuous at x = -1, since the denominator is zero. The domain of √u is u >= 0. So, we need x+6 >= 0 The domain of sin x is all reals, so it doesn't affect the result. we know that lim sin(x)/x = 1, so sin(2x)/(2x) is 1. So, lim sin(2x)/x = 2...
September 21, 2014

Algebra
The only question I see is whether x^3-2x^2-1+2 = 0 For some values of x, it is. I suspect a typo, since you have no x term, and two constant terms. Why not fix the typo and then ask your real question?
September 21, 2014

Math.
x - 8.77 = 23.40
September 21, 2014

math
2.3x = 48.00
September 21, 2014

Math
20*27 = ?
September 21, 2014

Math
100/200 = x/53.40
September 21, 2014

Math
what is the difference between 10 and 6? It is 10-6, or 4. So, the difference here is just x = 39.50 - 23.50
September 21, 2014

math
clearly (0,5) is is a set of x values, since x is in that interval. I'm sure it is just to restrict us to a single period of 2π. 1+x <= f(x) <= 3+sin πx as x->2, 1+2 <= f(x) <= 3
September 21, 2014

math
#1: c = 9.95 + .10m #2: c = 12.95 + .08m
September 21, 2014

maths
In triangles adb and adc, angle adb = angle adc bd = dc ad = ad So, the triangles are congruent, meaning ab = ac so abc is isosceles.
September 21, 2014

Algebra
correct
September 21, 2014

math
If the digits are a and b then 10a+b = 8(a+b) 10a+b - 45 = 10b + a The number is 72
September 21, 2014

Algebra 2 (Please, help me!)
well, it just means that all points have become 1/3 as far away from the origin as they were. Just divide all the coordinates by 3: (9,-6) -> (3,-2) and so on
September 21, 2014

math
the area grows as the square of the length ratio. So, the sides are in the ratio √9:√4 = 3:2. So also are the perimeters.
September 21, 2014

trigonometry
as usual, draw a diagram, and review your basic trig function definitions: tan θ = 5100/12000 So, θ = arctan(51/120)
September 21, 2014

Physics help ASAP
Suppose you are visiting a planet in a distant part of the galaxy.To determine the acceleration due to gravity on this planet, you drop a rock from a height of 55 m. The rock strikes the ground 1.9 s later.How many times greater is the acceleration due to gravity on this ...
September 20, 2014

Physics
A baseball is thrown upward with an initial speed of 35 m/s. What is the speed at t = 2 s?
September 20, 2014

physicas
A baseball is thrown upward with an initial speed of 35 m/s. What is the speed at t = 2 s?
September 20, 2014

Physics
A basketball is shot from an initial height of 2.4 m with an initial speed (v0 = 12 m/s) directed at an angle (35 degrees) above the horizontal. Additional information: Height of the basket is 3.05 m Find how far away the player is standing.
September 20, 2014

math
generally true, but the right angle is not at exactly 1:15, because the hour hand has also moved 1/4 of the way from 1 to 2. after m minutes, the minute hand has moved m/60*360 = 6m° the hour hand has moved to 30+m/2° So, we need to find m when 6m = 30 + m/2 + 90 11m/2...
September 20, 2014

Operating system
so, you expect us to do your research? I'd start with google, and then start reading.
September 20, 2014

Algebr
correct
September 20, 2014

math
the difference between two number m and n is m-n. So, you are comparing -14 and -10. The difference is -4 - (-10) = -4 + 10 = 6 That is, he lost 6 more ounces this year than last year.
September 20, 2014

Pre-Cal
but, at (1,-1), x^2+y^2 = 2 The maximum occurs when x = 2/√29 y = -5/√29
September 20, 2014

math
5h^(2/5) = 3645/5 h^(2/5) = 3645/25 h^(2/5) = 3^6/5 h^(1/5) = 27/√5 h = (27/√5)^5 That's an unusual result. I suspect a typo. If so, fix it and follow the same logic to arrive at the correct answer.
September 20, 2014

Algebra
you are correct.
September 20, 2014

Math
(b) recall that the vertex of a parabola is at t = -b/2a. In this case, that's 32/32 = 1. (a) just plug in t=1.
September 20, 2014

Algebra 2--Please, help me!
#1 ok #2 ok #3 right value, but not scientific notation #4 ok #5 Well, if it is a function, then no last name maps to more than one age. What do you think? #6 r(d) 75.00-3.50d I think you can answer the other parts of this one, no?
September 20, 2014

factorise completely
a(2x-3y) + (2x-3y) (a+1)(2x-3y)
September 20, 2014

math
Just start at -8 and start listing the odd numbers: -7 -5 -3 -1 1 3 5
September 20, 2014

Math
5/8 + 1/2 = 9/8 Only 7/8 were sick, so 2/8 had both
September 20, 2014

Math
13000/(1 - 2/5 - 1/6) = ?
September 20, 2014

Math (Equation of a circle)
clearly the radius is 2, since the center is at y=2. So, the equation is (x-3)^2 + (y-2)^2 = 4
September 20, 2014

Math
a^74/a^33 = 26p/-2p = -13 so, a = (-13)^(1/41)
September 20, 2014

math
246
September 19, 2014

math
x <= -2 has the filled dot at -2, but the shading continues all the way to the left. No idea what all those other values are supposed to be.
September 19, 2014

Business math
You need to find x where 12400(.042) = x(.0385)
September 19, 2014

math
to find how many times greater 6 is than 3, divide 6 by 3. So, for your birds, divide (13 9/10) by (3 1/2). Your answer 278/70 is the correct value, but it could be simplified to 139/35. Since 3.9714 is only approximate, it is hard to recover the fraction. Both your answers ...
September 19, 2014

Math Help
just replace all the x's with (x-1): f(x-1) = 4(x-1)^2 + 3(x-1) - 3 I assume you can simplify that.
September 19, 2014

Algebra 2
r(d) = 75.00 - 3.50d
September 19, 2014

Algebra 2
#3 is the correct value, but it is not scientific notation. The others are ok.
September 19, 2014

Math
Do a little simplification first. As long as x≠5, (x^2-25)/(x-5) = (x-5)(x+5)/(x-5) = x+5 So, what you have is, f(x) = x+5 if x <= -1 2x-3 if x > -1 So, since 4 > -1, f(4) = 8-3 = 5 And, since -1 <= -1, f(-1) = -1+5 = 4
September 19, 2014

math skill sheet 777
add up the values of 1 of each coin: 1+5+10+25 = 41 Now, how many 41's in 205? That's how many of each coin you have. so, now you can total up how many coins you have in total.
September 19, 2014

Math help
By "sum" I assume you mean the sum of three numbers in any row, with the center in each row. One way is surely to place the middle number (29) in the center. Then in pairs place the other numbers on ends of diameters, increasing on one end, decreasing on the other, ...
September 19, 2014

Math
No, D has the solution y=0 6y-2 = 2y-2 4y = 0 y=0 C is the one you want: 7x+5 = 7x+5 Both sides represent the same value, so any solution of the left side is also a solution on the right side.
September 19, 2014

Pre-Calculus Questions
(1) The slope is -6/6 = -1 So, in point-slope, we have y-3 = -1(x+5) Now massage that into slope-intercept form. Clearly, when x=0, y = -3 Since y = (x-3)(x+1), y=0 when x is -1 or 3. So, draw a parabola with those roots, which opens upward. Recall that the vertex occurs ...
September 19, 2014

physics
x(t) = Xo + Vot - 1/2 at^2 So, (5Vo - 25/2 a)-(4Vo - 16/2 a) = 100 (8Vo - 64/2 a)-(7Vo - 49/2 a) = 120 so, Vo = 70 a = -20/3 Now just figure x(20)-x(19)
September 19, 2014

Math
Just consider each ball's chances as it is drawn: 3/15 * 2/14 * 1/13 * 12/12 * 11/11 * ... = 1/455 Note that after all the red balls are drawn, there is a 100% chance that the rest will be white. Also, the order does not matter. If the order were WWRWWRWR the chances would...
September 19, 2014

Algebra 2 Answer Check
#3: Typo? I get 13xy #5: -2x^4y^7 / x^5 = -2y^7/x Now cube that. And watch that - sign
September 19, 2014

Math
Clearly a = 250000 r = 1/5 Now just use your sum formula.
September 19, 2014

MATHS
since sec^2 θ - tan^2 θ = 1, you have -8(sec^2 θ - tan^2 θ) = -8 Better review your basic identities. The most important is, of course, sin^2 θ + cos^2 θ = 1 divide through by cos^2 and you have tan^2 θ + 1 = sec^2 θ
September 19, 2014

Math
Surely you can determine T1 ?? Clearly d = -2b So now just apply your formulas.
September 19, 2014

Algebra 2
well, f(-x) = -x/(-x-1) = x/(x+1) ≠ -f(x) so no symmetry about (0,0) Also, f(-x) ≠ f(x), so no symmetry about the y-axis f^-1(x) = x/(x-1), so there is symmetry about the line y=x. See http://www.wolframalpha.com/input/?i=inverse+x%2F%28x-1%29
September 19, 2014

Algebra
Better review your symmetry section. No ideas on any of them?
September 19, 2014

Pages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Search
Members