Wednesday

February 10, 2016
Total # Posts: 37,540

**Plz My Maths**

This is just like the cloth problem. If there are m people and each one received n, then mn = 6500 (m+15)(n-30) = 6500 Now just solve for m and n. Why Do You Capitalize Every Word? It Is Rather Distracting. BUT NOT QUITE AS MUCH AS ALL CAPS, EH?
*January 6, 2016*

**MATH**

or, just start with what you are given: a point and a slope. Ding ding - use the point-slope form of the line: y+2 = -3/2 (x-3) now just rearrange stuff, and you will get Reiny's equation.
*January 6, 2016*

**math**

a = 3c b = a-6 b = 4d a+b+c+d = 39 (a,b,c,d) = (18,12,6,3)
*January 6, 2016*

**math**

if the figure is a parallelopiped, the bases have the same area. So, if the dimensions given are x,y,z, I'd say each base has area 2*6 = 12. your presentation is rather cryptic...
*January 6, 2016*

**math**

well, 1/4 = 2/8, so what do you think?
*January 6, 2016*

**Maths**

since cost is unitprice(p) times length (q), pq = 200 (p-2)(q+5) = 200 p = 10 Birr/m q = 20 m
*January 6, 2016*

**Math of Investment**

(1+.55/2)^(2n) = 2 I guess. Not sure of what your notation means.
*January 6, 2016*

**math**

what does "decreased by one of its one fourth" mean? decreased by 1/4, or decreased by 1/4 of its value? either n = d+5 or n = d-5 so, the new value is either (d+5)/(d+10) or (d-5)/(d+5) now equate that to whatever your weird statement implies.
*January 6, 2016*

**math**

cone: 1/3 πr^2 h hemisphere: 2/3 πr^3 sum: πr^2/3 (h+2r) Now just plug in your values.
*January 6, 2016*

**Math**

since the slope of the line is 1/2, tanθ = 1/2 = y/x. Now draw that triangle in QIII and you can see that cosθ = x/r = -2/√5
*January 6, 2016*

**Math**

since the median is the center value, at most half of the numbers can be positive.
*January 6, 2016*

**Algebra 1**

clearly it is not a whole number. Now you should note that the fraction is the ratio of two integers.
*January 5, 2016*

**Geometry**

5/x the enlargement ratio is newsize / oldsize
*January 5, 2016*

**Math**

You want a constant ratio, so (7+x)/(4+x) = (12+x)/(7+x) x = ?
*January 5, 2016*

**Algebra**

correct
*January 5, 2016*

**math algebra 2 using inverse variables**

no idea what an inverse variable is. you have listed two variables and their values. So what?
*January 5, 2016*

**Algebra 2**

in one year, 2.44 * 1.005^12 In n months, it will cost $5.00, when 2.44*1.005^n = 5.00
*January 5, 2016*

**Geometry**

Take a look at the angle bisector theorem. AB/AC = BD/DC
*January 5, 2016*

**maths**

factor out the 3, and you have x^2+x+24 = 0 No real solutions, since the discriminant is negative Use the quadratic formula to get the complex roots.
*January 5, 2016*

**Algebra 1**

NOOO It's (4,-7)! I explained how that pair fits both equations. try plugging in your numbers and see that they are waaaaaayyyy off!
*January 5, 2016*

**Algebra 1**

So, with the correct equations, you'd have to add them to eliminate y: 4x-y=23 7x+y=21 ------------- 11x=44 x=4 then plug that into either equation to figure out y.
*January 5, 2016*

**Algebra 1**

clearly there is a typo in the equations, or the answer key is wrong. The equations you gave have solution x = -2/3 y = -77/3 which you can check by plugging those values into both equations. (4,-7) is a solution to 4x-y=23 It is also a solution to 7x+y = 21, not the equation ...
*January 5, 2016*

**Algebra 1**

clearly you need to review the material on elimination. Google will provide lots of examples.
*January 5, 2016*

**Algebra 1**

elimination means that you manipulate the equations so that one of the variables is eliminated. Since the left sides are equal to the right sides, subtracting the left sides from each other and the right sides from each other gives a valid equation. You can see that if you ...
*January 5, 2016*

**Algebra 1**

just subtract one from the other to eliminate y: -3x = 2 Now you can get x, and then plug that in to get y.
*January 5, 2016*

**Log maths help me plz**

Hmmm. b = a^(3/2) d = c^(5/7) a = b^(2/3) c = d^(7/5) a-c=9, so b^(2/3) - d^(7/5) = 9 I assume we want integer solutions, so let's list the squares of cube roots and the 7th powers of 5th roots: n n^(2/3) 1 1 8 4 27 9 64 16 125 25 216 36 n n^(7/5) 1 1 32 128 243 2187 1024 ...
*January 5, 2016*

**PHYSICS**

assuming you meant speed, that would be 15*2π/2 = 15π m/min
*January 5, 2016*

**Equation help plz**

The equation is a circle with radius √14, centered at (-5,12) So, the minimum value of x^2+y^2 is the point on the circle nearest the origin. Since the center of the circle is 13 units away, the closest point on the circle is 13-√14 units away.
*January 5, 2016*

**math**

r^3 = 4375/35 = 125, so r=5 Now use that as you need to.
*January 5, 2016*

**Math**

LCM(8,7)=56, so the ages are in the ratios of 35:56:24 Since those three numbers add up to 115, they are also the ages.
*January 5, 2016*

**Math**

well, geez -- how about, um, substituting? You see that x = y-6, so substitute that into the other equation and you can then find y: y = 6-3(y-6) ...
*January 5, 2016*

**Math 11**

of what?
*January 5, 2016*

**Calculus**

y=1, and x=2 Bogus limits. Fix one or the other. In any case, the radius is 10-y and v = pi r^2 h
*January 4, 2016*

**calculus**

My bad. Using discs, the integral is v = ∫[0,1] π(R^2-r^2) dy where r = 1-√(1-y) and R = 1+√(1-y) v = ∫[0,1] π((1+√(1-y))^2-(1-√(1-y))^2) dy = ∫[0,1] 4π√(1-y) dy = 8π/3
*January 4, 2016*

**calculus**

Why don't you show your work? Using shells, try v = ∫[0,2] 2πrh dx where r = x and h=y=2x-x^2 v = ∫[0,2] 2πx(2x-x^2) dx = 8π/3 Using washers, we have v = ∫[0,1] π(R^2-r^2) dy where r = 1-√(1-y^2) and R = 1+√(1-y^2) v = &#...
*January 4, 2016*

**Calculus**

You're right. The boundaries are not clear to me either. http://www.wolframalpha.com/input/?i=plot+y%3D2sinxcosx%2C+y%3D2cosx
*January 4, 2016*

**Trigonomentry help plz thanks**

This is a challenge analytically, but using the graph it is easy: http://www.wolframalpha.com/input/?i=%28cosx%29^7%2B%28sinx%29^4%3D1 Coming up with the solutions -π/2, 0, π/2 is easy, but showing there are no others is tough.
*January 4, 2016*

**Bionomial expansion help agn #thanks**

The third term is C(6,2)(√x)^4(1/√y)^2 = 15x^2/y
*January 4, 2016*

**Calculus help plz i do not no it at all**

I seriously doubt it. Take a look at how wolframalpha interprets that: http://www.wolframalpha.com/input/?i=integral+x%E2%88%9A%282%2B3%E2%88%9C%28x^3%29%2F%28x^6%E2%88%9Ax%29%29 Maybe you can play around with your syntax till you get what you want.
*January 4, 2016*

**Calculus help plz i do not no it at all**

Do you mean x√(2+3∜(x^3)/(x^6√x))? I doubt it. How about some clear text with matched parentheses? If there are higher roots, just spell them out, as cuberoot(x), 4throot(x), etc.
*January 4, 2016*

**Word problem help plz**

oops. 85-41=44 Still no joy.
*January 4, 2016*

**Word problem help plz**

I guess by inverted you mean the digits are switched. So, if the father's age is xy and the son's age is ab, then we have 10x+y+10a+b=99 10a+b+10y+x=72 10x+y-(10b+a)=28 http://www.wolframalpha.com/input/?i=solve+10x%2By%2B10a%2Bb%3D99%2C+10a%2Bb%2B10y%2Bx%3D72%2C+10x%...
*January 4, 2016*

**Word problem help plz**

what is an "inverted age"?
*January 4, 2016*

**Algebra 1**

there is no solution to the given system.
*January 4, 2016*

**Algebra**

slope is 7, so y-0 = 7(x-0) or, y=7x
*January 4, 2016*

**ALEGEBRA 1**

clearly, y=y now substitute in the two different definitions. Draw the two lines. The solution is where they intersect.
*January 4, 2016*

**Math Complicated**

no, clearly it does not. The long bar over the sum means to evaluate everything under the bar, and then take the root of the result. Think of the long bar as a set of parentheses, as I showed above.
*January 4, 2016*

**Math Complicated**

No long lines online, but you can use parentheses: √(5 + 8 +24) = √37 since 5+8+24=37
*January 4, 2016*

**Math**

just add powers in products, and subtract in divisions: (6x^4)(4y^2) / [(3x^2)(16y)] = (6*4)/(3*16) * x^(4-2) * y^(2-1) = 1/2 x^2 y = x^2y/2
*January 4, 2016*

**Math**

Not sure what you mean by "make 3/5 to 21/25" 3/5 * 7/5 = 21/5
*January 4, 2016*

**Geometry**

yes, it is a "normal" trapezoid; it just means that its two non-parallel sides are not the same length. So, all you have to do is show that two of the sides of ABCD are parallel, and the others, not. Clearly, AB and CD are parallel, since they have the same slope. So...
*January 4, 2016*

**physics**

well, F = ma = 4200(3 + 10)
*January 4, 2016*

**geometry**

the surface area is just the sum of the two ends and the curved side. a = 2πr^2 + 2πrh = 2π*4*(4+12) Now just evaluate that on your calculator.
*January 4, 2016*

**Math**

whenever you have problems like this, draw a right triangle. In this case, you want a triangle with one angle x. If the sides are a,b,c with b opposite angle x, and c the hypotenuse, then sin(x) = b/c Now, the angle whose cosine is b/c is the other acute angle of the triangle...
*January 4, 2016*

**Maths**

3 times as many men means it takes 1/3 as long, right?
*January 4, 2016*

**Mathematics**

take a look at the point-slope form of a line, and you will see that yours is y-35 = 3/4 (x-40)
*January 4, 2016*

**engineering maths. need answer asap**

just conserve momentum before and after the collision. You then have 15*10 + 30*5 = (15+30)v
*January 4, 2016*

**math**

so, what's the difference between the area of a 12x12 square and a circle of diameter 12?
*January 4, 2016*

**Conversions**

all you have to do is add 273.15 to get the K temperature. That's not going to make much difference in 10^9 degrees.
*January 3, 2016*

**Geometry**

well, since all opposite sides of any parallelogram are parallel, it's not clear just what your question is.
*January 3, 2016*

**Math**

the answer cannot be 0,0. You are asked to find the coordinates of the vertices. Since the center of dilation is (0,0) and the scale factor is 4, just multiply all of the coordinates by 4.
*January 3, 2016*

**math**

since distance=speed*time, 2x = 4(x-4) x = 8 so, the distance is 2*8 = 16 miles each way
*January 3, 2016*

**math**

One way is to find the point on 13x+4y=32 which is at a distance of 4 from the line 3x+4y=28. Since the distance from (h,k) to ax+by+c=0 is |ah+bk+c|/√(a^2+b^2) and we know that k = (32-13h)/4, we have |3h+32-13h+28|/5 = 4 |-10h+60| = 20 h = 4 or 8 so, k = -5 or -18 ...
*January 3, 2016*

**Math**

correct. If you got that, I think your work must have been fine. It's due to the chain rule.
*January 3, 2016*

**Math**

domain of all exponentials is (-∞,∞) Range of a^x is (0,∞), so I'm sure you can adjust that as needed here. you know that the domain of √x is [0,∞), so now you just have to adjust to make sure that x-2 >= 0. As for the range, just recall ...
*January 3, 2016*

**Math**

Oops. I meant (c)
*January 3, 2016*

**Math**

Looks like (d) to me no constant difference no constant ratio
*January 3, 2016*

**Math**

beginning: at rest during: in circular motion end: at rest
*January 3, 2016*

**Math**

Ivan: 4.25+1.25m Vicky: 5.75+0.75m I+V: 4.25+1.25m+5.75+.75m = 10.00+2.00m = 2(5+m)
*January 3, 2016*

**Math**

well, you know that x=y-6, so, um, uh, substitute? y = 6-3(y-6) y=6 Now you can find x.
*January 3, 2016*

**mathematics**

well, 1.5 * 115 = 172.5 but that's not the $130 you say she has. Better fix up the question and post it as yo received it.
*January 3, 2016*

**Maths equation plz help urgently**

If you mean 10^x = 100, then clearly x=2, since 100=10*10 = 10^2
*January 3, 2016*

**trigonometry**

Since there are two angles of 55°, the vertex angle is 70°. So, each of the two matching sides has length 54/cos55° Now you can add up the sides to get the perimeter.
*January 3, 2016*

**algebra**

you have a point and a slope (2), so use the point-slope form: y-6 = 2(x-0) Now just rearrange the terms as needed.
*January 3, 2016*

**MATHS**

21 15/20 - 18 4/20 = ?
*January 3, 2016*

**maths lit, egd, civil , business studies**

maybe teach one of them?
*January 3, 2016*

**Math**

6 9/12 - 2 4/12 - 1 9/12 = ?
*January 3, 2016*

**math 7th grade connections**

d+g/h = 35+19/6 = 35+3.17 = 38.17 (d+g)/h = (35+19)/6 = 54/6 = 9 59+13n = 59+13*44 = 631 Something tells me you have trouble with the order of operations.
*January 3, 2016*

**Science**

Draw a triangle. If the plane's speed due north is v, then 60^2 + v^2 = 240 direction θ such that sinθ = 60/240
*January 3, 2016*

**geometry**

You need to explain a bit more how the angles and sides are positioned.
*January 2, 2016*

**MATHS**

Clearly the large cube is 6x6x6. So, how many 2x2x2 cubes is that?
*January 2, 2016*

**Algebra**

what? No ideas? The fee is constant.
*January 2, 2016*

**Calculus help plz**

I suspect a typo. Wolframalpha indicates that it cannot be done with elementary functions: http://www.wolframalpha.com/input/?i=integral+%28%28x%2B1%29%2F%28x-1%29%29^%281%2F3%29%2F%28x%2B1%29dx If I got it wrong, and only the (x+1) is in the cube root, it can then be done, ...
*January 2, 2016*

**math**

naturally, 1-.2 = .8
*January 2, 2016*

**physcis**

of course, you have to watch the units (2π√80 cm)/(10 m/s^2) mixes up cm and m. Convert cm to meters by (2π√80 cm)(1m/100cm)/(10 m/s^2) = π√80/500 s^2 = 0.056 s^2 An odd quantity, s^2
*January 1, 2016*

**math- HELP!**

Oww! My bad! Should have caught my typo. 26π*200 in/min The ridiculous speed of less than 1/2 inch per minute should have caught your eye!
*January 1, 2016*

**math- HELP!**

26π in/rev * 200rev/min = 26π/200 in/min w is not 200. It is 200*2π radians/min
*January 1, 2016*

**Math**

You have the equations x+y=−2 y=13x+2 You know it is a 2-D graph The lines intersect at (-2/7,-12/7), so none of the choices listing a different intersection can be right. That leaves only (A). Now you just have to check to see whether the lines pass through the named ...
*January 1, 2016*

**Math**

so, did you graph it? Which choice matches your findings?
*January 1, 2016*

**Math**

(x + 1/x)^2 = 3 x^2 + 2 + 1/x^2 = 3 x^4 - x^2 + 1 = 0 x = ±i^(1/3), ±i^(5/3) using i^(1/3), we have x^37 = i^12 i^(1/3) = i^(1/3) x^31 = i^10 i^(1/3) = -i^(1/3) x^47 = i^15 i^(2/3) = -i i^(2/3) x^26 = i^8 i^(2/3) = i^(2/3) x^63 = i^21 = i x^9 = i^3 = -i Looks ...
*January 1, 2016*

**Math**

5^3x = 65 3x log5 = log65 3x = log65/log5 x = log65/3log5 I assume you meant 2^(2x+3) = 80 (2x+3)log2 = log80 2x+3 = log80/log2 x = (log80/log2 - 3)/2
*January 1, 2016*

**science**

google is your friend. 1st hit solved the problem.
*January 1, 2016*

**computer programming**

use the function to calculate the nth fib #, and return its value. Then loop for p=1..5 and print each value returned.
*January 1, 2016*

**Calculus need help**

do you mean (x+x^3)/y or x + x^3/y ? It makes a difference
*January 1, 2016*

**Math**

(a) clearly, a = (5x+15)(31-2x) (b) I think you can graph a parabola (c) values for zero area (d) use what you know about parabolas (e) ditto (f) since this is a real-world situation, negative lengths are meaningless. So, D = [-3,31/2] R = [0,<value at vertex>]
*January 1, 2016*

**MATHS**

see related questions below.
*December 31, 2015*

**Algebra**

well, 1/12 of w is w/12 so, what's 4 more than that?
*December 31, 2015*

**Math**

y = (7/8)^x log(y) = x log(7/8) ... y=log12x 10^y = 12x ... and similarly for the last one.
*December 31, 2015*

**Calculus**

Each slice of water is a rectangle. Its length is 10. If the water has depth y, then the width of the rectangle is √(1 - (1-y)^2) = √(2y-y^2) Now you have to figure the water's depth (h), and the height to pump each slice of water is 2-y. So, you have to ...
*December 31, 2015*