Saturday

October 10, 2015
Total # Posts: 34,463

**math**

That would be 5000 * 1.15^4 It's just a GP, with a = 5000 r = 1.15
*September 7, 2015*

**Math**

Assuming the usual carelessness with parentheses, I'll interpret your expression as (2x^2)^(3/2)/((2^(1/2))*x^4) (2x^2)^(3/2) = 2^(3/2) * x^3 So, you have 2^(3/2) x^3 ---------------- = 2/x 2^(1/2) x^4
*September 7, 2015*

**algebra help me please**

A = 9/2 (b+35) 2A/9 = b+35 2A/9 - 35 = b
*September 7, 2015*

**algebra**

yes, it is, though I would have written it -(x-2) = 4 (why might that be?) Extra credit. What is a different correct step (not shown)?
*September 7, 2015*

**Precalculus**

Uese De Moivre's formula. (1-i)^10 = (√2 cis -π/4)^10 = 2^5 cis -10π/4 = 32 cis -π/2 = -32i (1+i)^20 = (√2 cis π/4)^20 = 2^10 cis 5π = -1024
*September 7, 2015*

**Math Trig**

if you set J at (0,0), then W is at (-500,200). Check your formulas, and you will find that the plane's heading (not bearing!) is 360-arctan(200/500)
*September 7, 2015*

**Math Trig**

First step. Draw the picture. Do you know the Pythagorean Theorem? Can you convert from x-y to headings?
*September 7, 2015*

**Math**

the circumference of the tire is the distance it moves in one revolution. So, what are the circumferences of the two tires? You want the difference, times 2 (for two revolutions)
*September 7, 2015*

**math**

clearly, p(LF) = 5/59 So, does that sound like it's where he usually hits? What does "usually" mean in terms of probability?
*September 7, 2015*

**Math**

well, how many days in 300000 minutes?
*September 7, 2015*

**numbers**

clearly the smaller digit is 1, since the larger digit cannot be greater than 9. The number must be 15 Check: 51 = 6+3*15
*September 7, 2015*

**Geometry**

the side length including the walkway is 6+20+8 = 32 Now you can find the perimeter. That's how much fence is needed!
*September 7, 2015*

**programmimg**

years+months = (years*12+m) months
*September 7, 2015*

**IMT**

.05 what?
*September 7, 2015*

**math**

I'll start. 9/(10*18)
*September 7, 2015*

**math**

5/8 + 7/10 25/40 + 28/40 53/40
*September 7, 2015*

**Maths**

might speedy, I must say! Oh -- was there a question in there somewhere?
*September 7, 2015*

**Algebra**

well, let's see. parallel lines have the same slope. I guess that leaves only perpendicular as the correct response. Surely a topic as basic as this is highlighted in a shaded box in your text! It can't possibly be as fast to post here and await a response as to simply...
*September 6, 2015*

**algebra**

Just work things normally: 21k – 3n + 9p > 3p + 12 21k - 3n > -6p + 12 7k - n > -2p + 4 -n > -2p - 7k + 4 n < 2p + 7k - 4
*September 6, 2015*

**math**

|x-32| <= 8 The cost must be within $8 of $32. So, what numbers are 8 below and 8 above 32?
*September 6, 2015*

**physics**

Your knowledge of projectile motion tells you that the range R and max height H are R = (v^2 sin2θ)/g H = (v sinθ)^2/2g You know θ,g,R,H so you should be able to come up with v.
*September 6, 2015*

**Math @Lee**

Here's a thought, Lee. Why not show us your calculations? Then we can (a) see what you meant to start with (b) see where you went wrong
*September 6, 2015*

**Math**

Must be a typo in either the question or the answers. I just note that 6*3/9+1 = 3
*September 6, 2015*

**Geometry**

Seems correct to me.
*September 6, 2015*

**@Damon**

It always seems like cheating to use a Taylor Series to prove a derivative... But nice of you to step in and help. It's clear that google is of no use to someone who cannot spell...
*September 6, 2015*

**Calculus using the first derivative**

do you mean the limit of the difference quotient? There are several good discussion of the topic online. Google is your friend.
*September 6, 2015*

**Physics**

90km/hr = 25m/s 128km/hr = 35.56m/s Let t=0 be the moment the speeder passes the cop. Then we want t when 35.56t = 25(t-1) + 1.40(t-1)^2 t = 11
*September 6, 2015*

**Pre-Calculus HELP!**

There's a nice discussion of this topic at http://laurashears.info/math122/unit4/polarAndParamFormsOfParabola/
*September 6, 2015*

**maths**

clearly it will take ten times as long for a single man to do the job.
*September 6, 2015*

**Caculus**

with a hint like that, what troubles you? The only wrinkle is that (x-1) > 0 for x > 1 (x-1) < 0 for x < 1 to check your work, enter your function at wolframalpha.com, and it will show the graph.
*September 6, 2015*

**math**

As always, draw a diagram. If the height is h, and the distance is d, you have h/d = tan 60° h/(d+100) = tan 30° Now just solve for d and h.
*September 6, 2015*

**algebra**

Hmmm. Looks like a typical govt school... Recall that complementary angles add to 90°, so you want x where x + 72°40' = 90°0'
*September 6, 2015*

**Algebra**

recall your differences of squares factoring: a^2-b^2 - (a+b)(a-b) So, here you just have (9p)^2 - (7q)^2
*September 6, 2015*

**Algebra**

well, (x+5)^2 = x^1+10x+25, so ...
*September 6, 2015*

**Algebra**

You have u^2+v^2, where u = 2ab v = 5cd As you know, (u+v)^2 = u^2+2uv+v^2 Now just plugin your substitutions.
*September 6, 2015*

**Subj: Physics school: omar samatar secondary school**

v0 + 4a = 16 v0 + 10a = 28 a=2, v0=8 s(t) = s0+ 8t + t^2 Now you can figure the distance traveled during any interval.
*September 5, 2015*

**Math**

you have two 5-12-13 triangles. Since the two sides of 12 are joined as a single line, add up all the sides and subtract 12 twice for the interior sides. If that seems hard, just draw the figure, label the exposed sides, and do the math.
*September 5, 2015*

**Algebra I**

time = distance/speed You have the speed. Look up the distance and do the math.
*September 5, 2015*

**Algebra I**

no solutions, since that would mean that 4-b = 2-b 4 = 2
*September 5, 2015*

**UNAM**

it would be (.25*.015 + .125*.050)/(.015+.050) = 0.1538M
*September 5, 2015*

**physics**

since the ball went straight up, its has zero velocity at maximum height. So, what does that say about its momentum?
*September 5, 2015*

**numerical analysis**

well, you know that f(0) = -2 f(pi/2) = pi/2 So, start with those two values a1 = 0, b1=pi/2 so, c1 = pi/2-(pi/2)(pi/2-0)/(pi/2-(-2)) = 0.88 f(c1)=f(0.88) = 0.421 Since f(c1) > 0, a2 = a1, b2 = c1 = 0.421 I assume you can follow the method, as explained at https://en....
*September 5, 2015*

**Algebra**

Only true if a > 0. If a<0, then you have x < b/a or x<c.
*September 5, 2015*

**PRE CALCULUS**

In 8 years, the share price rose by 3.86, making the rate of change (slope) 3.86/8 = 0.4825 per year. So, since we started measuring at the $0.18 price, at t=5, the price p(t) is p-0.18 = 0.4825(t-5) Now you can find p(t) for other values of t. The other problem is worked in ...
*September 4, 2015*

**math**

If a line (-9,7) is marked by e which is a ratio of 1/4 then where is e on the line? My answer is -7
*September 4, 2015*

**Math - My Bad**

ignore my question. Ms Sue read it right
*September 4, 2015*

**math**

does each 4.5ft fence section have an and piece, or does the entire fence have two end pieces (one on each end)?
*September 4, 2015*

**math**

does 3x - 4x = x?
*September 4, 2015*

**Geometry**

In a Hexagon net for a 3 dimensional solid how many regions would there be? My answer is 8 the 6 sides and the top and bottom
*September 4, 2015*

**ALgebra**

take a look at the graph: .05v^2+1.20v <= 40 http://www.wolframalpha.com/input/?i=1.20v%2B.05v^2+%3C%3D+40 Though I don't see how the car will come to a stop.
*September 4, 2015*

**Counting Numbers**

zero. No square ends in 7. Only 1,4,5,6,9,0 Poke around a bit and you will quickly see why.
*September 4, 2015*

**MATH**

come on. adding a negative number is the same as subtracting a positive one. 6-4 = 6+(-4) Think of it as moving left and right on the number line. Subtracting 4 means moving left 4 places. So does adding -4.
*September 4, 2015*

**MATH**

you can think of it as (-3)(x+3) + (-2)(x+4)
*September 4, 2015*

**statistics**

Assuming I parsed the garbled English correctly, I agree that C was the correct choice. You really gotta work on your typing.
*September 4, 2015*

**Math**

0.42
*September 4, 2015*

**Algebra**

we have a winner!
*September 4, 2015*

**Algebra**

correct
*September 4, 2015*

**Algebra**

y=42x
*September 4, 2015*

**math**

Draw the diagram. It is clear that angle PQR is 90° in a 3-4-5 triangle. So, PR = 5km As for the direction, you can either figure the x- and y-coordinates of R, or note that angle QRP is arcsin(4/5), and add that to the diagram.
*September 4, 2015*

**Science**

Depends on how fast the car was moving at the start.
*September 4, 2015*

**math**

(15/2) / (9/4) = 15/2 * 4/9 = 10/3 = 3 1/3 So, 3 whole pieces.
*September 4, 2015*

**Math**

Do not expand first. So, let u = 5y+1. I'm sure you can solve u^2 + 5u + 6 = 0 (u+3)(u+2) = 0 u = -3 or -2 That means you now need to solve 5y+1 = -3 or 5y+1 = -2 No problem now, eh?
*September 4, 2015*

**Math- Algebra**

n-2 = c
*September 4, 2015*

**Math- Algebra - eh?**

help you do what?
*September 4, 2015*

**Algebra**

this is just the difference of two squares, so you have ((x+5)+(x-5))*((x+5)-(x-5)) = (2x)(10) = 20x If you expand it all out, you will easily see that everything but the x terms cancel out.
*September 4, 2015*

**calculus**

a = 24-15√t v = 24t-10t^(3/2) s = 12t^2 - 4t^(5/2) s=0 when 12-4√t = 0, or t=9 a(9) = 24-15√9 = -21
*September 4, 2015*

**Physics/trig**

consider what would happen if the plane were flying horizontally. The shadow would be moving exactly as fast as the plane. What if the plane were flying vertically? Shadow would not move. So, it's easy to see that if the plane is rising at an angle θ, the horizontal ...
*September 3, 2015*

**math**

no. Taking it as written, 3r+b/a+y = w 3r = w-y - b/a 3r = (wa-ya-b)/a r = (wa-ya-b)/(3a) If you meant (3r+b)/a + y = w (3r+b)/a = w-y 3r+b = aw-ay r = (aw-ay-b)/3 Maybe if you use some parentheses things will be clearer.
*September 3, 2015*

**algerbra**

1/4(x-h)=p+c x-h = 4(p+c) x = h + 4(p+c)
*September 3, 2015*

**math**

correct
*September 3, 2015*

**algebra**

W = 2L-10 So, 2(2L-10 + L) = 70 Now find L, then W.
*September 3, 2015*

**Math**

There are 54+92+12=158 total songs Of those, 54+92 = 146 are not classical. So, now what do you think?
*September 3, 2015*

**algebra**

I find the explanation of the problem quite unclear. Here is one guess: If you mean the volume of the material used, then if the outside radius is R, and the inside radius is r, the volume of material is 2π/3 (R^3-r^3) Assuming the outside radius is 40ft and the thickness...
*September 3, 2015*

**algebra**

3(a^2+b) - 4(a^2-b) 3a^2 + 3b - 4a^2 + 4b -a^2 + 7b
*September 3, 2015*

**Math**

If there were x 2-pointers and y 3-pointers, then we have x+y=8 2x+3y=18
*September 3, 2015*

**lee**

57632
*September 3, 2015*

**Math (Ratios)**

6/6 would be my choice
*September 3, 2015*

**algebra**

correct
*September 3, 2015*

**Pre-Calculus**

slope zero means y is constant. At x=0, y=9 so, the equation is y=9
*September 3, 2015*

**precalc**

D: all reals R: 2 no zeros or asymptotes not 1-1 continuous constant bounded If this one gave you trouble, you have a bumpy ride ahead!
*September 3, 2015*

**Math**

n is a perfect square means that there is a rational number k such that k*k = n Then k is the square root. The others are clearly false, since √5 is not rational √(3/5) is not rational Therefore, certainly not (d)
*September 3, 2015*

**algebra**

clearly the answer is A or B, since you want to find the time. Hint: since you want to find the time, it must be the dependent quantity. Hence, (A) is the answer.
*September 3, 2015*

**Algebra**

d-20 = 2(k-20)+16 d+k = 70 Now go for it.
*September 3, 2015*

**Precalc Math**

every repeating decimal of n digits, say, abc can be written as abc/999 where the denominator of n digits is 10^9-1 So, .23 = 23/99 5.23 = 5 23/99 = 518/99 You should have written 100x = 523.23... x = 5.23... 99x = 518 x = 518/99 If there are n repeating digits, multiply by 10^n
*September 3, 2015*

**Alg 2**

1B 5C 6C 12B
*September 3, 2015*

**math**

ok except for the last. √5 is irrational, so any rational multiple of it is also irrational. (A) (C) is the only imposible choice. Every real number is either rational or irrational, but cannot be both or neither.
*September 3, 2015*

**geometry**

the midpoint has coordinates (x,y) that are the average of the endpoints. So, (3+x)/2 = 5 (5+y)/2 = -11 Or, you can reason that 5 2 larger than 3, so the x-coordinate of v will be another 2 larger. Same for y.
*September 3, 2015*

**geometry**

the angle is bisected into two equal parts, so x-3 = 2x-13
*September 3, 2015*

**geometry**

google is your friend. For example, see http://www.mathsisfun.com/geometry/construct-linebisect.html
*September 3, 2015*

**cms**

.25(300) = .20(300+x) Or, since the concentration is being reduced by a factor of 4/5, the volume is increasing by a factor of 5/4. The additional volume is 1/4 of 300.
*September 3, 2015*

**Calculus (limits)**

look on the graph. Where you would find f(2), does the line approach the same value from both sides? If so, that value is the limit.
*September 3, 2015*

**Algebra**

7*14 + 170 = (7+2w)(14+2w) Now solve for w
*September 3, 2015*

**math**

better review the distributive property. associative would be (6a+2a)+8b = 6a+(2a+8b)
*September 3, 2015*

**mathematics**

The digits are x and x+1, so (10x + x+1) = 5/6 (10(x+1)+x) Now you can find x. Extra credit: How did I know which digit came first?
*September 3, 2015*

**Algebra 2**

5r+4 <= 5 5r <= 1 r <= 1/5 I assume you can graph that on the number line.
*September 3, 2015*

**sjpuc**

If the swimmer's speed is s and the water's speed is w, we have s+w = 60 s-w = 8 I think you can now find s and w, no?
*September 3, 2015*

**Algebra. Please check my answers**

4^5 means 4 to the 5th power, or 1024 I suspect you meant something else. -(12x-8y) means -1(12x-8y) so you must use the distributive rule: -(12x-8y) = (-1)(12x) + (-1)(-8y) = -12x+8y So, (C) Your answer simply ignored the outside minus sign. It is the same as +(12-8y)
*September 3, 2015*

**Algebra**

#1 ok #2 ok, since 6/(x+y) isn't in the list #3 nope. What does quotient mean?
*September 3, 2015*

**MATH**

what does nCr4 mean? Try writing things as C(n,r+2) etc to make the arguments clear.
*September 3, 2015*