Thursday

September 29, 2016
Total # Posts: 44,207

**Algebra2**

Solve the system by elimination. -2x+2y+3z=0 -2x-y+z=-3 2x+3y+3z=5

*September 18, 2016*

**mount ayliff comprehensive high school**

Go west, young man.

*September 18, 2016*

**algebra**

x: side of smaller square x+4: side of larger square (x+4)^2 = 4x^2 - 14

*September 18, 2016*

**math**

3:1 = 540:180

*September 18, 2016*

**Algebra**

see related questions below

*September 18, 2016*

**maths**

50 sin70° time to review the basic trig functions and right triangles. And ships sail on headings, not bearings.

*September 18, 2016*

**mathematical physics**

well, you have M = xy N = x^2y^2 so the integral is just ∫∫R (Nx - My) dx dy Along y=0, dy=0, Along x=1, dx=0, Along y=2x, dy = 2dx Now just break the boundary into three parts, and evaluate each part. Watch the direction of the limits.

*September 18, 2016*

**Maths**

net fill rate: 40L/min so figure the volume filled in 15 min.

*September 18, 2016*

**science**

Try retyping using the characters < <= > >=

*September 18, 2016*

**Maths Exponents**

11 x 10^-5 = 1.1 x 10^-4 The distance would be 1.496E11 - 3.84E8 = 1.496E11 - 0.00348E11 = ...

*September 17, 2016*

**mathematics**

work with the costs for x km: 250+.22x 96+.5x

*September 17, 2016*

**Math**

Online you needed parentheses so things are not ambiguous. You want a common denominator, so note that x^2+x-12 = (x+4)(x-3) x^2-16 = (x+4)(x-4) Now you can see that the LCD is (x+4)(x-4)(x-3) and work with that.

*September 17, 2016*

**Math**

as with all problems of addition of fractions, you want the LCD. In this case, that is 30m. Now add things up the way you always do with fractions.

*September 17, 2016*

**maths need help**

I'll take a stab and say that the road is 1m away from the field. So its inner radius is 41 and its outer radius is 42. So, the cost is rate * area = π(42^2 - 41^2) * 26

*September 17, 2016*

**math**

what are all these broken lines? Just type the numbers you want to use. And if you want to use fractions, just type them normally, as in 3/4, 1/8, etc. I spell copy/paste from some word processor. A big clue is the garbled line feeds and the em-dash minus signs.

*September 17, 2016*

**English**

thank you

*September 17, 2016*

**English**

What type of pronoun is used in the following Sentence Under the most splendid house in the city is still to be found the cellar where they store their roots as of old? a- personal b- reflexive c- indefinaite d- interrogative my answer is a

*September 17, 2016*

**Advanced Functions 12**

You need f(f^-1(x)) = x -√(x^2-2 + 2) = -√(x^2) = -x this fails because x^2 is not one-to-one

*September 17, 2016*

**PRE-CAL**

can't see the table, but you have correctly solved for t.

*September 17, 2016*

**Math**

so, what are you trying? Apparently you have done some work, so show us how far you got. It's probably just something simple.

*September 17, 2016*

**math**

since e+e = e e=0 now pick any h&m that add to less than 10

*September 17, 2016*

**algebra**

Fix your typo. You have two "=" signs Your choices are garbled, as well.

*September 17, 2016*

**Business maths**

if the cost is c and the marked price is p, then .70 * p = 1.25c = c+91 .25c = 91 c = 364 p = 1.25*364/.7 = 650

*September 17, 2016*

**Math**

using the quadratic formula, we have x = [-(k+2)±√((k+2)^2 + 12k)]/2k For the roots to be real, we need (k+2)^2 + 12k >= 0 -8-√60 <= k <= -8+√60 Now, we want the roots to be positive, so we need [-(k+2)±√((k+2)^2 + 12k)]/2k > 0

*September 17, 2016*

**math**

π*45^2*130 --------------- 1.2445

*September 17, 2016*

**Math**

rice: 11/18 (7/18 left) tomatoes: (3/7)(7/18) = 3/18 (4/18 left) spinach: (1/4)(4/18) = 1/18 (3/18 left) ...

*September 17, 2016*

**maths**

ok. that was fun.

*September 17, 2016*

**Maths**

.3x + 20 = .8x

*September 17, 2016*

**College Algebra**

your functions are correct. You need to find out what syntax the software expects. Maybe you could try using fractions: D(t) = t/20 0<=t<=25 5/4 25<t<=40 5/4 + t/60 40<t<=70 or maybe the x's confused it.

*September 17, 2016*

**Maths**

try figuring how many do contain a five? Then subtract that from the number of 3-digit values.

*September 17, 2016*

**maths**

eh? eh? try using some parentheses, as you can see that the online formatting is poor. At least some spaces, to indicate breaks. And are those exponents, as in m^3 = m cubed

*September 17, 2016*

**algebra**

(3 ozAg) * (1 ozAu)/(s oz Ag) * $d/(10 ozAu) = $(3d / 10s)

*September 17, 2016*

**Math**

correct

*September 16, 2016*

**Math**

$3.60 * (2/6) = $1.20

*September 16, 2016*

**algebra**

w(w+4) = 7w+18

*September 16, 2016*

**Algebra**

4*86 <= 84+84+88+x <= 4*90

*September 16, 2016*

**Advanced Functions 122**

for every integer k, x = k*360°, y is undefined.

*September 16, 2016*

**Advanced Functions 12**

if I decipher the question correctly, the answer is no. y = x^3 + 4 has odd end behavior, but is not an odd function.

*September 16, 2016*

**linear programming**

or visit http://www.zweigmedia.com/RealWorld/LPGrapher/lpg.html and it will show you how it's done

*September 16, 2016*

**partial maths**

wolframalpha.com can verify your answer. http://www.wolframalpha.com/input/?i=partial+fractions+x%5E3%2F(5x%5E3-1) This one is kinda nasty, since 5x^3-1 does factor, but not with integer coefficients. It's a difference of two cubes, so it factors as (∛5 x - 1)(∛...

*September 16, 2016*

**statistics**

total points: 10*24 = 240 after removal of 42, you have 9 scores with a total of 198. So, ...

*September 16, 2016*

**maths helpppppp me asap plz**

∑1/n diverges, so there is no LUB

*September 16, 2016*

**math**

Come on - this one is easy. You have z+7+5 ends in 4 7+5=12, so z=2 Now work with that same idea to get x. Remember that no one said that x,y,z had to be different from all the other digits already present.

*September 16, 2016*

**calculus plz help me**

r = (1+y'^2)^(3/2) / |y"| y^2 = 4ax, so y = 2√(ax) y' = a/√(ax) y" = -a^2/(2(ax)^(3/2)) = -a/(2x√(ax)) so just plug it in: (1+y'^2) = 1+a/x r = ((a+x)/x)^3/2 * 2x√(ax)/a = 2(a+x)^(3/2) / √a

*September 16, 2016*

**algebra - incomplete**

I guess that would depend on the size of the lids, eh?

*September 16, 2016*

**College Algebra**

1/4 of a complete circle, so π/2 (16^2 - 12^2) in^2 that's assuming that the blade extends to the end of the wiper arm. how do you now what automobiles suppose?

*September 16, 2016*

**calculus need help**

Just use the formula: r = (1+y'^2)^(3/2) / |y"| 3ay^2 = x^3-2ax^2+ax 6ay y' = 3x^2-4ax+a y' = (3x^2-4ax+a)/(6ay) y" = [(6ay)(6x-4a) - (3x^2-4ax+a)(6ay')]/(36a^2y^2) Now just plug in (3a,2a) and crank it out. Messy algebra, but not difficult.

*September 16, 2016*

**Physics**

for each body, F=ma So, get the acceleration, and then using s = 1/2 at^2 add the two distances and find t when their sum is 504m

*September 16, 2016*

**math**

2/9 v - 2/3 v = -4/9 v so, you have -4/9 v = 1 v = -9/4 You are clearly just guessing, or there are typos in your problems Did you actually try your answer to see whether it made the equation true?

*September 16, 2016*

**math**

I assume you mean (1/3)(b+4) = 1/2 b+4 = 3/2 b = -5/2 If you really want b=2, then 1/3 * (2+4) = 1/3 * 6 = 2 not 1/2

*September 16, 2016*

**Physics**

h(t) = 3.00 + 17.8 sin53.0˚ - 4.9t^2 find t when h=0 Then, recall that the upward speed is vy = 17.8 sin53.0˚ - 9.8t vx = 17.8 cos53.0˚ the final v is of course found by v^2 = vx^2 + vy^2

*September 16, 2016*

**Science**

well of course you don't. That's why I told you that distance = speed * time So, for each part of the trip, multiply the speed by the time. Then add those two numbers.

*September 16, 2016*

**Science**

wrong. distance = speed * time, not speed/time (and you can't figure 80/1 = 80?) If you had watched your units, you'd have seen that (60km/hr) / (2hr) = 30 km/hr^2 when you wanted km

*September 16, 2016*

**math**

$200/30hr = $6.67/hr

*September 16, 2016*

**math**

since all 4 sides are equal, the base is 6. A = bh = 42 h = 7

*September 16, 2016*

**Algebra**

just do what you always do. It does not matter whether the symbols are variables or constants. a(x+y) + bz + c = d ax + ay = d-bz-c ax = d-ay-bz-c x = (d-ay-bz-c)/a Clearly, a cannot be zero. Otherwise, all's fair in love and algebra.

*September 16, 2016*

**Math**

and even lots of apostrophes! (well, one, anyway)

*September 16, 2016*

**maths**

or, it is 5log3 - (3log2 + log3 + log5) - (log2 + 3log3) + (log3 + 2log5) + (3log2 + log3) - 3log3 - log5 + log2 = 0

*September 16, 2016*

**math**

Suppose there are x people in A and 2x people in B. Now figure the total weight and divide by the total population.

*September 16, 2016*

**Physics**

initial upward speed is 20 m/s h(t) = 160 + 20t - 4.9t^2 when is h=0?

*September 16, 2016*

**Math**

Let's say that the three times to traverse AB,BC,CD are x,y,z respectively. They add to 5 min. The time to accelerate is the same as the time to decelerate, so x=z. If the acceleration is a m/s^2, we have x+y+z = 5 1/2 ax^2 = axy 1/2 ax^2 = axz - 1/2 az^2 We can factor out...

*September 15, 2016*

**physics**

when the can passes, 256 - 4.9t^2 = 256 - 32.0t use that value of t for v = -9.8t

*September 15, 2016*

**Physics**

you know that (a) R = v^2/9.8 sin2θ (b) h(t) = v*sinθ - 4.9t^2 solve for h=0

*September 15, 2016*

**Algebraic expression**

yes, that is an expression

*September 15, 2016*

**Physics**

42 micro-tons

*September 15, 2016*

**Maths**

is this 4 separate problems? If so, do them all the same way: just add up the quantities: (a) 250+150 = 400

*September 15, 2016*

**math**

V(t) = 51500 - (51500-43200)/3 t Now just find t when V=0.

*September 15, 2016*

**Calculus AB**

f(0) is undefined, but the limit is -1 at x=0. So, there's a removable discontinuity at x=0. Naturally, at x=1, f is undefined; there's an asymptote there. Take a look at the graph for further justification of your analysis: http://www.wolframalpha.com/input/?i=ln%7Cx-...

*September 15, 2016*

**Math**

no. no matter how you "express" a number, it does not change its value.

*September 15, 2016*

**Math**

under power h = 14.7*4^2 = 235.2 v = 29.4*4 = 117.6 on a ballistic path, h = 235.2 + 117.6t - 4.9t^2 max height is at t = 117.6/9.8 plug that into h to find the height.

*September 15, 2016*

**Math**

ok - I'll assume that that you have had some physics exercises where you have learned that with acceleration a and initial velocity v, s = vt + 1/2 at^2 Since v went from 0 to 6 in 6 seconds, a = 6/6 = 1 m/s^2 So, to get the distance during acceleration, you have s = 0*6...

*September 15, 2016*

**Math**

if you have not studied calculus yet, what methods have you studied that relate distance to speed? There must be similar problems in your text.

*September 15, 2016*

**Math**

distance is the integral of the velocity. You have defined v(t) as a piecewise function. v(t) = t for 0<=t<=6 6-(3/2)(t-6) for 6<=t<=10 the distance is thus ∫[0,6] t dt + ∫[6,10] 15-(3/2)t dt

*September 15, 2016*

**Algebra II**

y = kx So, y/x = k is a constant. You want x such that (-5/8)/(3/2) = (2/5)/x x = -24/25

*September 15, 2016*

**math**

nope. not if all the socks of one color are identical. In any case, you have not defined what an event is. If the event is "pick a sock" then there are 2 outcomes: B or W.

*September 15, 2016*

**Algebra**

$54,922 But he's gonna get his legs broken long before the bill is that high.

*September 15, 2016*

**Math**

if there are $x at 13%, then the rest (7000-x) is at 2%. So, just add up the interest from each. It needs to be $300: .13x + .02(7000-x) = 300

*September 15, 2016*

**Math**

when you're dealing with quantities where getting the nearest 100 is good enough. That's the whole point of rounding. If you're estimating the size of a concert crowd, who cares whether there are 1623 or 1630 people there? You might want to say that there are ...

*September 15, 2016*

**math**

http://www.jiskha.com/display.cgi?id=1473970501 now start thinking some. You can answer all the other questions using those functions. Recall that x represents the number of months. Use it to figure the membership costs involved.

*September 15, 2016*

**Math**

well, how much do you add to get to the next consecutive integer?

*September 15, 2016*

**math**

Using the functions I already gave you: G = 59.00 + 19.50x W = 149.00 + 9.50x you want to find when the costs are equal. Well, duh -- set the two values equal and see which value of x makes it so: 59.00 + 19.50x = 149.00 + 9.50x 10x = 90 x = 9

*September 15, 2016*

**math**

already did. can you make a stab at this one? Use the equations I gave you earlier.

*September 15, 2016*

**math**

G = 59.00 + 19.50x W = 149.00 + 9.50x Next I suppose you'll ask which is a better buy, or when the costs are equal. First, try to figure that out using the above functions.

*September 15, 2016*

**Physics**

I agree on B inst. vel. is the slope of the line at a point.

*September 15, 2016*

**Math (pls check my answers!!)**

correct

*September 15, 2016*

**Geometry**

If we call the midpoint M, then the coordinates of M are halfway from U to V. M = (5,-11) = (3,5)+(2,-16) V = (5,-11) + (2,-16) = (7,-27)

*September 15, 2016*

**PHYSICS**

still no question there. But the speed home is 7/3 the speed leaving

*September 15, 2016*

**Math**

correct

*September 15, 2016*

**Algebra**

nope. since |4| = 4, -|4| = -4

*September 15, 2016*

**Maths**

sinA/(1-cosA) = cot(A/2) that should help. you are correct on the 2nd term.

*September 15, 2016*

**math**

the ratios are 3:1:2

*September 15, 2016*

**math**

5*1.5*1000/150

*September 15, 2016*

**Math**

since distance = speed * time, 120t = 105(t + 1/3) solve for t, then find the distance

*September 15, 2016*

**Maths**

on any two consecutive days, 1/15 + 1/20 = 7/60 of the job is done So, after 8 pairs (16) days, 56/60 = 14/15 of the job is done A finishes the job on day 17.

*September 15, 2016*

**Algebra**

the slopes of the line segments are: AB: 1/3 AC: 2 BC: -3 So, AB and BC are perpendicular You could also calculate the lengths of the sides, and see whether a^2+b^2 = c^2 for one of the pairs of sides. Too much work

*September 15, 2016*

**mathematics**

#1: x^2 + 9^2 = 9.6^2 #2: the triangle is isosceles.

*September 15, 2016*

**College Algebra**

for every $1 price increase, sales decrease by 150. So, Now you can use the point-slope form of the line: x-375 = -150(p-2.50) x = 750 - 150p

*September 15, 2016*

**math**

2y + 2xy' - 2yy' = 0 y'(2x-2y) = -2y y' = y/(y-x) y" = (y'(y-x) - y(y'-1))/(y-x)^2 = (-xy'+y)/(y-x)^2 = (-x(y/(y-x)+y)/(y-x)^2 = ((-xy+y(y-x))/(y-x)^3 = (y^2-2xy)/(y-x)^3

*September 15, 2016*