Friday

October 9, 2015
Total # Posts: 34,441

**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*

**Calculus**

AB+BC = AC so, AB+BC+CD = AD BC-DC = BC+CD = BD See if you can use that idea to rearrange +/- terms so the ends line up in order
*September 22, 2015*

**Math**

c = 3p, so adding up all the feet, we have 2(3p)+4p = 2400 10p = 2400 so, there are 240 pigs c-p = 3p-p = 2p, so there are 480 more chickens than pigs.
*September 22, 2015*

**math**

well, 4+20 = 24
*September 22, 2015*

**Math**

what does Moran have to do with it?
*September 22, 2015*

**Calculus**

the left and right limits are the same at every point, and the function must be defined at every point. Intuitively, there are no holes in the graph.
*September 22, 2015*

**Math**

clearly, it is 18/40 Since I have no idea what part of the spinner is colored red, I cannot give a theoretical probability. If you pay attention to details (such as spelling) you can post a coherent problem...
*September 22, 2015*

**algebra**

since -x is just (-1)(x), and exponents are done first, -a^2 = -(a^2) = -(2^2) = -(4) = -4 on the other hand, if you want to do the minus first, you need to say (-2)^2 = (-2)(-2) = +4
*September 22, 2015*

**Math**

25.0m^3 * (3.28ft/m)^3 * $2.35/ft^3 = $2070.00
*September 22, 2015*

**Math**

if you multiply everything by 12, you have 4m + 3m - 12 = 30 Can you handle that?
*September 22, 2015*

**Math**

t(1/2 + 1/6) = 2 t(2/3) = 2 t = 2(3/2) t = 3 Or, you can multiply everything by 6 to get 3t + t = 12 t = 3
*September 22, 2015*

**Geometry**

how about just multiplying the section length (1.25m) by the number of sections (11)?
*September 22, 2015*

**Math**

8x^2+40x+32 = 8(x^2+5x+4) = 8(x+4)(x+1) So, (8x^2+40x+32)/(x+4) = 8(x+1) at every value of x except x = -4. So, the limit as you approach x = -4 is just 8(-4+1) = -24. The graph has a hole at x = -4, since 0/0 is not defined. But everywhere else, no matter how close, f(x) = 8(...
*September 22, 2015*

**maths**

Is 6 double 2? I think you want 64282
*September 22, 2015*

**math**

(1,2)(0,1)(8,9) Looks like there are eight of them. So, list them.
*September 22, 2015*

**Math**

well, 6+5 = 11 The rest is given
*September 22, 2015*

**precalculus**

For the point (-5,4) x = -5 y = 4 r = √41 cosθ = x/r = -5/√41 = -.781 cscθ = r/y = √41/4 = 1.601 Clearly the point is in QII ! How did you come up with your values?
*September 22, 2015*

**precalculus**

of course not. You know that cosθ is never greater than 1 or less than -1. Similarly, cscθ is never less than 1. Given a point (x,y), r^2 = x^2+y^2 cosθ = x/r cscθ = r/y Also, given that cosθ<0 and cscθ>0. tanθ cannot be positive.
*September 22, 2015*

**Precalc**

surely you have some ideas about these. #6 is cos,sec #1,#5 are the same functions
*September 22, 2015*

**Algebra**

If A and C are x, then B = x/5. So .02x + .10(x/5) + .16x = 1.00
*September 22, 2015*

**Algebra**

If x at 20%, then .20x + .05(10-x) = .14(10)
*September 22, 2015*

**Algebra**

well, set them equal: 40.74x + 742.65 = 47.93x + 725 Now just find x and add 1995.
*September 22, 2015*

**Math**

the area increases by a factor or (5/2)^2 So, just plug in the new numbers.
*September 22, 2015*

**physics**

v = √(2as) so, just plug in the numbers
*September 22, 2015*