Tuesday

November 24, 2015
Total # Posts: 35,768

**Math**

j=s+72, so s = j-72 t=s s=k+50, so k=s-50=j-122 j+k+s+t <= 502 j+k+2s <= 502 j+j-122+j-72 <= 502 3j-194 <= 502 3j <= 696 j <= 232
*September 25, 2015*

**Physics**

wow - what a lot of words. Just specify stuff with symbols, ok? r(t) = (3t^3-2t)i + (5-2t^4)j v(t) = (9t^2-1)i -8t^3 j a(t) = 18t i - 24t^2 j (d) at t=3, dr/dt = v(3) = 26i-216j so, tanθ = -216/26
*September 25, 2015*

**Algebra**

For m minutes, we want A >= B. So 13+0.06m >= 0+0.08m
*September 25, 2015*

**f5 math**

80/(x+2) = 80/x - 2
*September 25, 2015*

**Calculus 1**

well, if x>=0, |x|=x, so we have y = x/√(5-x^2) y' = 5/(5-x^2)^(3/2) At x=2, y'=5 So, the line through (2,2) with slope=5 is y-2 = 5(x-2) See this at http://www.wolframalpha.com/input/?i=plot+y%3D|x|%2F%E2%88%9A%285-+x^2%29%2C+y%3D5%28x-2%29%2B2+for+0%3C%3Dx%...
*September 25, 2015*

**Algebra**

(1200-500)/24
*September 25, 2015*

**algebra**

Looks the same to me :-)
*September 24, 2015*

**math**

after 24 minutes, they synch up.
*September 24, 2015*

**College Algebra**

solve for t years in 5000(1+.075/4)^(4t) = 7900
*September 24, 2015*

**College Algebra**

what is the half-life? If it is N years, then you need to solve for t in (1/2)^(t/N) = 0.25 Expect the answer to be just a bit over one half-life...
*September 24, 2015*

**Algebra**

you know that the amount remaining after t minutes is f(t) = 13 e^(-kt) Now you know that 13 e^(-20k) = 4.5 k = 0.053, so f(t) = 13 e^(-0.053t) Now you want the alarm to sound when p(t) = 2. So, just find t where 13 e^(-0.053t) = 2.0
*September 24, 2015*

**Pre Calculus**

Note that 80 minutes is 8 doubling periods, for a growth of 2^8 = 256 times. So, initially there were 50000/256 bacteria. I think you can take it from there, no?
*September 24, 2015*

**Math**

(3/4)/8 = 3/32 (1/3)/4 = 1/12 LCD(32,12) = 96 3/32 + 1/12 = 9/96 + 8/96 = 17/96
*September 24, 2015*

**Geometry**

G = 180-F = 180-(90-E) = 90+E = 90+(90-D) = 180-D = 180-(180-C) = C
*September 24, 2015*

**Math**

well, just multiply each ingredient by 5 1/2. For the granola, that's (1 1/2)(5 1/2) = 3/2 * 11/2 = 33/4 = 8 1/4 and so on
*September 24, 2015*

**math for managers**

and it is the line through (-5,2) with slope 2/3
*September 24, 2015*

**Math**

see the response at http://www.jiskha.com/display.cgi?id=1443138556 which you posted 3 minutes ago!
*September 24, 2015*

**math**

(a) looks like zero to me. Just because a sock has (possibly quite small) red dots or stripes does not make me want to call it "red."
*September 24, 2015*

**Math**

since the base of the larger triangle is twice as big as that of the smaller one, the height is also twice as big.
*September 24, 2015*

**math**

or even 84n
*September 24, 2015*

**math**

technically, yes, in that it gives the right result. I sort of think they were looking for 7*4n*3
*September 24, 2015*

**algebra**

well, naturally, that would be 7/(3+7)
*September 24, 2015*

**Physics?**

see related questions below
*September 24, 2015*

**Quick Algebra Help**

|w-300| <= 20 So, what are two numbers that are 20 away from 300?
*September 24, 2015*

**Math**

zero is not positive. So, you have to shift by at least 2 to get both roots positive integers.
*September 24, 2015*

**Calculus**

Well, you know that x^3 does not intersect any straight line in more than one place, but it's not factorable. So, what numeric techniques have you learned? False position, Newton's method, bisection? Just looking at a graph probably won't get you to three places ...
*September 24, 2015*

**physic**

well, the x speed (v cosθ) is clearly 121.9/5 m/s Now you can get the y-speed and θ, and work out the range.
*September 24, 2015*

**physic**

y(t) = 34.8 sin44.5° t - 4.9t^2 x(t) = 34.8 cos44.5° t Now just find when dy/dx = -tan20.6° recall that dy/dx = (dy/dt) / (dx/dt)
*September 24, 2015*

**physics doublecheck?**

well, if -69.972 is not right, then there may be an error in the answer key. Did you try 69.972, since it just asks for speed, not velocity? I can't see where I did anything wrong. Maybe someone else can spot a mistake.
*September 24, 2015*

**physics**

what, you can't plug in t=7.14 into -9.8t?
*September 24, 2015*

**physics**

time to intercept: 323-35.0t = 323-4.9t^2 t = 7.14 http://www.wolframalpha.com/input/?i=323-35.0t+%3D+323-4.9t^2 Now, knowing that the can has speed v = -9.8t figure it out.
*September 24, 2015*

**math**

#9. Suppose I said 4 = d/7 Could you solve that for d? Well, follow the same steps for your problem. #10: add y to both sides, subtract 10 from both sides. Then y is all alone.
*September 24, 2015*

**Math**

almost any number with a power of ten between -7 and +7
*September 24, 2015*

**math**

The question is poorly worded, since it leaves out the cost of the checks. You've gone as far as you can. Clearly, $7/mo is less than $10/mo, but you have to factor in the number of checks. You have found that at 12 checks, the cost is the same for both banks. Any more ...
*September 24, 2015*

**CICI**

I agree. Except that the image is magnified, not the actual specimen!
*September 24, 2015*

**chemistry question**

Clearly, from the chemical formula, for each mole of Ca(OH)2 there are 1 mole Ca 2 moles O 2 moles H
*September 24, 2015*

**Algebra**

If Tom takes x minutes, then you need to solve for x in 1/90 + 1/x = 1/36
*September 24, 2015*

**Object oriented programming**

see related questions below
*September 24, 2015*

**Algebra**

probably something like x+7 = 30 Be more precise. Here, x does not just represent the number of cds That is unclear and ambiguous. It represents the number of cds already on the shelf.
*September 24, 2015*

**Math**

5c * 1L/4.22cup = = 1.18 L
*September 24, 2015*

**Music**

#1 is garbled, but I think your answer is wrong. A whole rest occupies the same time as a whole note: generally 4 beats. But, if the time signature is 2/2, that would be just two beats. #3 ok #4 8? really, how much is 3/4 of 16? Not 8. #5 1/8 = 2/16. So, 6/16 = 3/8
*September 24, 2015*

**Alegbra 1**

well, you want x + 2/15 > 1/2 x > 1/2 - 2/15 x > 11/30 So, which of the choices fits that condition?
*September 24, 2015*

**calculus**

since constants do not change, f' = 0 Or, if you want to use the power rule, f = 2 x^0 f' = 0 * x^-1 = 0 g = 3x^4+6x^3-1 g' = 12x^3+18x^2
*September 24, 2015*

**Math**

since there's a quadratic in the bottom, and a linear factor in the top, it's a good bet you can massage it into something like du/u. In fact, if we let u = 3x^2+3x+5 du = 6x+3 = 3(2x+1) and you have ∫ 1/3 du/u = 1/3 log u + C = 1/3 log(3x^2+3x+5) + C
*September 24, 2015*

**Calculus**

surely you can just look it up. a derivation can be found at http://www.petervis.com/mathematics/maclaurin_series/maclaurin_series_tanx.html
*September 24, 2015*

**math**

descent time: 4.25 min hover time: 12.75 min 19.125 - 4.25-12.75 = 2.125 min So, the ascent rate was (-28.9 - (-79.9))ft/2.125min = 24.0 ft/min
*September 24, 2015*

**Geometry**

Point a could be anywhere. Where does it lie in relation to b,c,d?
*September 24, 2015*

**Geometry**

ec bisects <bed, m<<aeb =11x-12 and m<ced =4x+1. Find m<aec
*September 24, 2015*

**Math**

c'mon, guy, think. Clearly the length of the wire is 44 cm. So, for a circle to have a circumference of 44 cm, you need a radius given by 2πr = 44 r = 22/π And the area would be πr^2 = π(22/π)^2 = 484/π
*September 24, 2015*

**Math**

well, 121 = 11^2
*September 24, 2015*

**Calculus 1**

the easy way is to notice that this is just y = tanh(3u) y' = -3sech^2(3u) or, using the exponentials, that's 12/(e^3u + e^-3u)^2 or (12e^6u)/(e^6u + 1)^2
*September 24, 2015*

**math**

s = b+6 s-5 = 3/2 (b-5) so, s-5 = 3/2(s-6-5) s-5 = 3/2 (s-11) 2s-10 = 3s-33 s = 23
*September 24, 2015*

**Calc- Limits**

clearly he wants lim x/lnx as x->1 since that value approaches 1/0, the limit is undefined.
*September 23, 2015*

**Physics(which cone will land first)**

since mass varies as the scale cubed (volume), and area varies as the scale squared, the larger cone has a higher weight:area ratio, so it should have a higher terminal velocity. I'm assuming the air resistance varies directly with the area. If that is not so, my logic may...
*September 23, 2015*

**Algebra 2**

4(x-6)^2 = x^2 Now just solve for x
*September 23, 2015*

**Math**

see previous post for method and example
*September 23, 2015*

**Math(HELP!!!) PLEASE**

1 mile is 16093.44 dm, so you have 1.5 mi^2 * (16093.44 dm/mi)^2
*September 23, 2015*

**math**

no, 3x = 5y-7 So, 6x = 2(5y-7)
*September 23, 2015*

**math**

from the 2nd equation, 3x = 5y-7 so the 1st equation becomes 2(5y-7)-2y+1 = 0 Now solve that for y, then figure x.
*September 23, 2015*

**Quick algebra help**

#1: |x+5|+2 #2: -(x+8)^2 type that stuff in at wolframalpha.com and you can see the results. #2 is at http://www.wolframalpha.com/input/?i=plot+plot+x^2%2C-%28x%2B8%29^2+for+-20%3C%3Dx%3C%3D20
*September 23, 2015*

**Algebra**

you want m where 19.3(1.089^m) = 138 1.089^m = 7.150 m log1.089 = log7.150 m = log 1.089 / log 7.150
*September 23, 2015*

**Algebra**

just solve for t in (1-0.10)^t = 0.5 .9^t = .5 t = log 0.5 / log 0.9
*September 23, 2015*

**math**

5*4 = 20 so, 21 is the next largest integer This assumes that p and q are close to 5 and 4. If p=40.27 and q=95.154, 21 is not the next largest integer.
*September 23, 2015*

**pre-calculus**

If there are x lbs of cashews, then the rest (10-x) are almonds. So, add up the costs: 9x + 5(10-x) = 8(10)
*September 23, 2015*

**Math**

4 4/8 + 2 5/8 = ...
*September 23, 2015*

**Math (vector addition)**

as usual, x = r cosθ y = r sinθ
*September 23, 2015*

**math**

A+B+C = 180 (C/5)+(C+26)+C = 180 Now solve for C, and then find A and B. or, using A, A+(5A+26)+5A = 180
*September 23, 2015*

**Algebra**

Since there are only 2 colors, 3 draws must produce 2 of one or the other.
*September 23, 2015*

**Math**

in each case, multiply by the denominator, then add the numerators. For example -1 + 17/13 = (-13+17)/13 = 4/13
*September 23, 2015*

**Math**

go to wolframalpha.com and type in your expression
*September 23, 2015*

**geometry**

psq
*September 23, 2015*

**Math**

determine the slope of the line you want use point-slope form convert to slope-intercept #2 is thus slope of given line is -1/2 perp. line has slope 2 y-1 = 2(x-4) y = 2x-7 Luckily, that line also passes through (1,-5)
*September 23, 2015*

**W**

a very similar question was solved below: http://www.jiskha.com/display.cgi?id=1316469592
*September 23, 2015*

**Algebra**

If they lost x, then x + x+62 = 160
*September 23, 2015*

**MATHS**

cost = 12z-27s Now plug in whatever other quantities you want to use.
*September 23, 2015*

**calculus**

come on - this is Algebra I; no problem for a calculus student, right? 5(x^2+4)^4(2x)(x-2)^4+(x^2+4)^5(4)(x-2)^3 = 2(x^2+4)^4 (x-2)^3 (5(x-2)x + (x^2+4)2) = 2(x^2+4)^4 (x-2)^3 (7x^2-10x+8) now take a stab at the others. Look for common factors, one by one. Factor out the ...
*September 23, 2015*

**calculus**

f(x) is continuous, except where the denominator is zero. So, where is 1-cos(x) = 0?
*September 23, 2015*

**math**

g=18 j=2g+4 = 40 k=j-15 = 25 ...
*September 23, 2015*

**Math**

4 divided by 8 = 1/2 How did that help you come up with a=32?
*September 23, 2015*

**Physics**

Draw a velocity diagram. You will see that tanθ = horizontalspeed/verticalspeed
*September 23, 2015*

**Chemistry 151**

how many moles of AlCl3 is .2580g? Look at the formula for the compound. You will have 3 times that many moles of Cl ions.
*September 23, 2015*

**algebra I**

x/3 + x/2 >= x-3 2x + 3x >= 6x-18 -x >= -18 x <= 18
*September 23, 2015*

**Algebra 1**

A is correct D is (x+3)*8
*September 23, 2015*

**Math**

P(head) is 1/2 for any coin, no matter how many you have already seen.
*September 23, 2015*

**chemistry**

density is mass/volume, so mass = density*volume 2.5L*3g/cm^3 is 7.5, but the units are wrong 2.5L * 1000cm^3/L * 3g/cm^3 = 7500g or 7.5kg
*September 23, 2015*

**math**

All of your work is good. It seems your teacher is fixated on making sure you don't do anything in your head. If you set them up as I did, even the most OCD teacher should be satisfied. Good work
*September 23, 2015*

**math**

7. Anne is seven years younger than her brother, Brandon. Anne is 23. Let B represent Brandon’s age. A = B-7 so, B = A+7 A = 23 B = 23+7 = 30 Cougars lost to the Tigers in basketball by 15 points. The Tigers scored 72 points. Let C represent the Cougars' score. C = T...
*September 23, 2015*

**IPC**

((35.0-20.0) m/s) / (4.00 m/s^2) = 3.75s
*September 23, 2015*

**math**

as usual, draw a diagram and review your basic trig functions. L/50.0 = tan 59°30'
*September 23, 2015*

**Science**

If you say so...
*September 23, 2015*

**Science**

oh, please. If you plant bean seeds in several different environments, don't they all come up beans?
*September 23, 2015*

**green valley college**

First step: balance the equation
*September 23, 2015*

**MATH**

4x^2
*September 23, 2015*

**al 1**

x/3 + x/2 = 3/4 x(1/3 + 1/2) = 3/4 x(5/6) = 3/4 x = (3/4)(6/5) x = 18/20 = 9/10 Or, you could clear fractions by multiplying by 12: x/3 + x/2 = 3/4 4x + 6x = 9 10x = 9 x = 9/10
*September 23, 2015*

**math homework**

so, what does the band decide? That is the independent variable. The rest is dependent.
*September 23, 2015*

**math**

7^6 / 7^1 = 7^(6-1) = 7^5 What you have is just 7*7*7*7*7*7 ----------------- 7 one of the 7's cancels, leaving 5 more on top: 7^5
*September 23, 2015*

**MATH**

You want v=20, so, just solve 3t^2-6t-7 = 20 If you put in t=20, that will give you the velocity after 20 seconds. C'mon - think about what the variables mean...
*September 22, 2015*

**math**

multiply everything by 2 and you have 5d-3 = -1 Can you handle that?
*September 22, 2015*

**Calculus**

you need to review addition of vectors. AB starts at A and ends at B BC starts at B and ends at C So, AB+BC starts at A and ends at C. ABC form a triangle. google will provide lots of illustrations and examples of vector addition
*September 22, 2015*