Sunday
August 28, 2016

Posts by STEVE

Total # Posts: 42,827

math
120% = 6/5 y + 6/5 y = 550
July 23, 2016

math
a 25% increase is a factor of 5/4 So, you need 4/5 of the width for the area to stay the same (5/4 l)(4/5 w) = lw So, what % decrease is 4/5?
July 23, 2016

Math
see related questions below. Just solve 7.8+3.5sin[pi/6(t-3)] = 10.29
July 23, 2016

Math
(9^x)^2 + 4(9^x) - 21 = 0 (9^x + 7)(9^x - 3) = 0 ...
July 23, 2016

Math
300*1.055^n = 3000
July 23, 2016

math
5/8 - 1/4 = 3/8 So, 3/8 x = 15
July 23, 2016

math
so what's the trouble? They gave you the equation y = R(p)-C(p) = N(p)*p - C(p) = -p(p+5)(p-17) - (75+12(-(p+5)(p-17))) = (12-p)(p+5)(p-17) - 75 You can expand that if you want. What does it mean? Revenue-Cost = Profit.
July 23, 2016

math
Fix the typo. And do you mean 6/(2x-y) ?
July 23, 2016

Algebra
since the area scales by the square of the linear factor, the sides are in the ratio √(32/63) = √(16*2 / 9*7) = 4/3 √(2/7) I'll let you take it from there.
July 23, 2016

physics
get out your graph paper and plot the motion. Clearly the distance walked is 10+5 = 15 Now, where did he end up? How far is that from where he started?
July 23, 2016

mathematics
a+9d = 40 + a+4d a+14d = 127 solve for a and d, then find S30 = 30/2 (2a+29d)
July 23, 2016

Math
x(x+2) = 195 find x, and then x+2 p = 2(x + x+2)
July 23, 2016

Physics
time to accelerate 10m/s / 4m/s^2 = 2.5s deceleration takes twice as long, since the rate is half as great. Now figure the distance using the good old formula s = vot + 1/2 at^2 for each part of the trip.
July 23, 2016

Math
good work, but if you are going to include the units in your expressions, it is important to be careful with them: 48hours x 5seconds=240 hour-seconds what you need to do is make sure that the units cancel properly. 48hr x 5s/hr = 240s
July 23, 2016

Linear equations in 1 variable
Add up their value: 5x + 2(3x) = 77 Now find x and thus 3x.
July 23, 2016

Maths
2(x+y) = 62 xy = 198 x+y=31 y = 31-x x(31-x) = 198 x^2-31x+198 = 0 (x-9)(x-22) = 0 ...
July 22, 2016

math
a(bx-c) = d-(x+e) abx-ac=d-x-e (ab+1)x = ac+d-e x = (ac+d-e)/(ab+1)
July 22, 2016

Math
Hmmm. 7.8sin (pi/6(t-3)) = 10.29 sin (pi/6(t-3)) = 1.319 <--- ?? I suspect that you have left out a term in the definition of h(t). Fix it and then proceed with the solution.
July 22, 2016

Math
2 trenches = 3*5 = 15 man-hr 7 trenches = 7/2 * 15 = 105/2 man-hr (105/2 man-hr) / (5 man) = 21/2 hr or, 10 hr 30 min
July 22, 2016

RE
The only thing you have to remember is that since the two sides of an equation are equal (hence the name), if you do the same thing to both sides, they remain equal. Your goal is to isolate the variable on one side, so the other side is just its value. Now, when you say you ...
July 22, 2016

math
well, you know that the equation for a parabola with vertex at (0,0) directrix y = -p is x^2 = 4py Your parabola has been shifted so the vertex is at (-2,4), so you want (x+2)^2 = 4p(y-4) Your directrix is at y = 1, which is 3 units below the vertex, so p=3 (x+2)^2 = 12(y-4) ...
July 22, 2016

math
log1/2(x-1)+log1/2(x+1)-log1/√2(7-x)=1 You seriously need to learn how to use parentheses. Also, the final result will depend on the base of the logarithms. I shall assume base 10. Assuming you meant log(1/(2(x-1)))+log(1/(2(x+1)))-log(1/(√2(7-x)))=1 log (1/(2(x-1...
July 22, 2016

Maths
the height on the nth bounce is 100*0.8^n So, the geometric sequence for the bounces is a = 100 r = 0.8 Each bounce is a round trip, except for the 0th trip, so the distance traveled is 2*100/0.2 - 100 = 900 ft The real-world distance of course will be slightly less than that.
July 22, 2016

math
the number who passed either or both is 30+20-8 = 42 so, ...
July 22, 2016

math
or, since 15 = 3*5, multiply by 5/5 and you have 3/7 = 15/x 15/35 = 15/x x = 35
July 22, 2016

Calculus
well, x is cut off both sides, and x is the box's height, so v(x) = (18-2x)(12-2x)(x)
July 22, 2016

math
Divide the $420 into 10 parts of $42 each. A gets 3 parts, or $126 B gets 7 parts, or $294 In order for A to get 180, either B gets 420 or a gets 3/7 of the total, not 3/7 of B's share.
July 22, 2016

Futher maths
I'll just use x, for ease of typing tanx + 2secx = 2cotx + 3cscx A strange mixture of functions, so I'll just use sine and cos: sinx/cosx + 2/cosx = 2cosx/sinx + 3/sinx (sinx+2)/cosx = (2cosx+3)/sinx So, assuming that cosx and sinx are nonzero, sinx(sinx+2)-cosx(2cosx+...
July 22, 2016

Math
what's the problem? Just calculate the distance and time as needed, and the average speed is distance/time. For (a), A-B is 25km A-C is 10km So, B-C is 15km C-A takes 1.5 hr B-A takes 3.5 hr stop at C takes 0.5 hr So, the B-C leg takes 1.5 hr 15km/1.5hr = 10km/hr The rest ...
July 22, 2016

English
zombie apocalypse runaway vehicle fire army ants avalanche chainsaw maniac
July 22, 2016

Math
if you review the definition of the cotangent function, then you can see that with a height of h, h cot19° - h cot37° = 60
July 21, 2016

Physics
each bulb is a separate branch of the circuit, and so has the same voltage drop. Since they have the same resistance, each bulb gets a current of 1.5V/6.3Ω = 0.238A Note that 1/Rt = 0.317, so Rt = 3.15 = 6.3/2 Ω
July 21, 2016

math
one measurement is worth a thousand expert opinions. Buy some chips, fill the jar. Empty them out, count them. In the interest of accuracy, it will be best to eat the chips and repeat with a new batch. Maybe several times!
July 21, 2016

Civics.
I agree with D, but I'd hardly consider Brazil a smaller country. Its area is bigger than the continental USA, and it has vast natural resources. Granted, a lot of them are in the jungle, and that makes them harder to extract.
July 21, 2016

Msth
actually, keeping track of the units, 1,130mi / 25mi/gal = _______ gallons Multiply the gallons by $2.60/gal to get the dollars
July 21, 2016

Physics
G(M)(2M)/(3x)^2 = KGM^2/x^2 2GM^2/9x^2 = KGM^2/x^2 2/9 = K
July 21, 2016

statistic
Consult your Z table to see how many std away leaves 4.5% Multiply that by 0.36 and add it to the mean. Play around with Z table stuff at http://davidmlane.com/hyperstat/z_table.html
July 21, 2016

math
pair them up in this way: -35,35 -34,34 ... The sum of all those pairs is zero. So, which numbers are left over? Add them up.
July 21, 2016

math
after a 30% markup the price is cost * 1.30 After a 15% discount, the price is cost * 1.30 * 0.85 = cost * 1.105 That price is $99, so 1.105 * cost = 99 cost = 99/1.105 = 89.59
July 21, 2016

math
cost * 1.30 * (1-0.15) = 99 cost = 99/1.105 = 89.59
July 21, 2016

Math CSET
There is no easy way. The actual math formula is simple, but hard to do by hand. I suggest that you just have to know the values for 1,2,3 std from the mean. Just as it is best if you just know the trig values for common angles.
July 21, 2016

Algebra
Assuming "a rate at x rate per min" means "a rate of x ft per min", then 4000 - xy
July 21, 2016

PHYSICS
will squash you like a bug.
July 21, 2016

algebra - incomplete
sorry - you need another equation.
July 21, 2016

Electric Circuits
I = E/R Now just plug in your numbers.
July 21, 2016

general math
K(x) = 15.00x for x <= 50 12.50x for 50 < x <= 75 Apparently you had some choices, but they're not here. I got my answer by reading the text provided. How else?
July 21, 2016

math
LCM(25,30) = 150 minutes 11:00 + 2:30 = 13:30, or 1:30 pm
July 21, 2016

math
Reiny did this one already. See the related questions below.
July 21, 2016

Physics or Math
The Toyota goes 350km in 5 hours. The Kia has gone the same distance in 7 hours. So, the Kia's speed must be 50 km/hr
July 21, 2016

math
for the triangle, 6*5 = 1/2 * 12 * h Now, knowing h, the side length s can be found using s^2 = 6^2 + h^2 For the towers, the distance z is z^2 = 16^2 + (40-10)^2
July 21, 2016

Physics
distance = time * speed. So, 5*70 = (5+2)*x
July 21, 2016

Calc
we want to maximize xyz subject to the constraint that 5xy+3(xy+2xz+2yz) = 1000 Using Lagrange multipliers, we find that x=y, and λ=2.1516 and z=4λ That means a local max occurs at (6.455,6.455,8.607) A nice article on Lagrange multipliers, with an example similar to...
July 20, 2016

Geometry
see earlier post better yet, graph the two functions and see the shifts
July 20, 2016

Geometry
I think she meant y=(x−5)^2+5 → y=(x−0)^2+0 shift left 5 and down 5
July 20, 2016

Chemistry
DrBob222 did it last night. See the related questions below.
July 20, 2016

maths - sloppy
The rectangle is x meters what? wide? long? do you mean x m^2, the area?
July 20, 2016

Math
There are 4 cubes per foot, so in terms of cubes, the prism is 8/14 x 4 x 5 Since you want whole cubes you are out of luck, since 2/14 < 1/4, the size of a cube. I suspect a typo. Fix it and then apply the logic.
July 20, 2016

Math
draw your triangle. secθ = r/x and x<0, so θ is in QII or QIII x = -3 r = √20 y = ±√11 Now just recall that tanθ = y/x, so it will be ±√11/3, depending on the quadrant.
July 20, 2016

Physics
I'm sure you have seen examples of this simple circuit. (a) R = 2+3 (b) 1/R = 1/2 + 1/3 I = E/R in each case.
July 20, 2016

physics
2r/πr = 2/π π/2 is the ratio between its distance traveled (πr) and its displacement (2r).
July 20, 2016

math
right you are. Should be "greatest." If I had to choose (and I don't) I'd assume sloppiness and pick 11.
July 20, 2016

mathematics
I'd say zero, since today is Wednesday!
July 20, 2016

math
a = b*l = b * b^2 = b^3 da/dt = 3b^2 db/dt 40 = 3*64 db/dt db/dt = 5/24 l = b^2 dl/dt = 2b db/dt = 2*8 * 5/24 = 10/3
July 20, 2016

math
hmmm. where is D? If your inequalities hold, then clearly CD < AC < AD
July 20, 2016

math
draw a diagram. Review your basic trig functions. Now it is clear that if the height is h ft, h cot 78°15' + h cot 59°47' = 500
July 20, 2016

Physics
.001s * 340m/s = 0.340m
July 20, 2016

valuemath
No ratio given for cows and goats. But, the sheep:goats ratio is 15:20
July 20, 2016

Math
4a(b) = a(2b)-24 4(b^2-2b) = (2b)^2-2(2b)-24 4b^2-8b = 4b^2-4b-24 4b = 24 b = 6
July 19, 2016

Math
e*f is constant, so you want e such that (1/3)e = 9*3
July 19, 2016

Math
Looks like Benjamin to me, but do it the same way: p^1/3 = (8x)^1/6 p^2 = 8x x^-1/2 = 4^-1/4 x^-2/4 = 4^-1/4 x^-2 = 4^-1 x^2 = 4 x = 2 p^2 = 16 4y = |p-8| 4y = 8 y = 2
July 19, 2016

Math
4 - 3y < 10 3y > 14 y > 14/3 = 4 2/3 -y-8 > -14 y < 6 so, how many integers are there between 4 2/3 and 6?
July 19, 2016

math
yes, you do (-4-6)^2 + (-14-10)^2 = 10^2+24^2 = 26^2
July 19, 2016

math
The result above is the length of the path from home to courthouse and then on to office. the distance z from home:(6,10) to office:(-4,-14) is This is just a scaled-up 5-12-13 triangle, being 10-24-26.
July 19, 2016

math
presumably we want to find the original area to be shoveled. If that was x, then x(1/5 - 2/5) = 200
July 19, 2016

maths
If he marks up r%, then (1+r)c*.70 = 1.1c 1+r = 1.1/.7 r = 1.1/.7-1 = 0.57 = 57% or 4/7 Check: cost = 14 1.57*14 = 22 22*.7 = 15.4 = 14 * 1.10
July 19, 2016

math
with respect to what? Let's do r if y' = dy/dr, 2yy' = 4p y' = 2p/y y" = -2p/y^2 y' = -4p^2/y^3
July 19, 2016

Physics
after a distance s, v = 2√(5s+10) - 10
July 19, 2016

Physics
the k component has doubled. So, the others must also, giving 4i+6j+2k
July 19, 2016

Physics
just check and see that A = 3B
July 19, 2016

Physics
R = 2h
July 19, 2016

Physics
the article in wikipedia gives the formulas, which I'm sure you already have. Just divide H/R and simplify. https://en.wikipedia.org/wiki/Trajectory
July 19, 2016

Physics
see related questions below. just figure how long it takes to fall, then calculate the distance flown in that time.
July 19, 2016

Physics
just figure the mass of water, and recall that water has a density of 1g/cm^3 No idea what the unknown liquid has to do with anything.
July 19, 2016

pre cal
∛(2/(1-x)) (-7±√(4x^2+49))/2 which branch depends on the domain of f(x)
July 19, 2016

pre cal
If the point (40,3) is on the graph of y=f(x), what point must be on the graph of y=8f(8x) (5,24) just solve x+13 = -12 x = -25 y = -(-8/4-13) = 15 So, the new graph must contain (-25,15) similarly for the other one.
July 19, 2016

Physics
so, how long does it take to fall 0.75 meters? 4.9t^2 = 0.75 Using that time value, the constant horizontal speed is 2.0m/ts = 2.0/t m/s
July 19, 2016

Math
see related questions below. In particular, http://www.jiskha.com/display.cgi?id=1468483941
July 19, 2016

calculus
so, if the divisions are x meters long, we have 4*3 + 6x <= 100 6x <= 88 x <= 44/3 so, 8 <= x <= 44/3
July 19, 2016

math
The curved part (and maybe the base) is just half the surface area of the cone, for which I'm sure you have the formula. The interior which is exposed is just a triangle. Its area is also easy to find.
July 19, 2016

Math
2500(1+r/4)^(4*10) = 6000 (1+r/4)^40 = 2.4 1+r/4 = 1.022128 r/4 = 0.022128 r = 0.0885 = 8.85%
July 19, 2016

Fpb science
mumble mumble
July 18, 2016

Busn math
(3/35) / (9/7) = 3/35 * 7/9 = 3*7 / 35*9 = 3*7 / 5*7*3*3 = 1 / 5*3 = 1/15 or, you could do it (3/35) / (45/35) = 3/45 = 1/15
July 18, 2016

Math (PLEASE HELP!)
just in case you are having trouble solving exponential equations, eliminate k and you have 2 - 2^(-1-h) = -1 - 2^(-3-h) 3 = 2^(-1-h) - 2^(-3-h) 3 = 2^-h/2 - 2^-h/8 3 = 2^-h (1/2 - 1/8) 3 = 2^-h * 3/8 8 = 2^-h h = -3 Then k = -2, and g(x) = 2^(x+3)-2 See the graph at http://...
July 18, 2016

Math (PLEASE HELP!)
2^(-1-h)+k = 2 2^(-3-h)+k = -1 solve for h and k Of course many other values for b could have been chosen, but since only two data points were given, something had to be assumed.
July 18, 2016

math
20 + .15x = 35 + .10x
July 18, 2016

Calculus rate of change
A and B are ok. As for C, just showing that f" is a quadratic does not mean that it has two roots. However, if you went ahead and found that it must have two roots because the discriminant is positive, then ok. f is concave up (down) if f" is positive (negative), so ...
July 18, 2016

Calculus @Reiny
huh? height is twice the diameter, not half h = 4r Make that change, Nicole, and redo the steps.
July 18, 2016

physics
50mi/hr = 22.35m/s 22.35m/s / 4.5m/s^2 = 4.97s Now just plug in for distance: s = vt - 1/2 at^2
July 18, 2016

physics
the driver of the truck going 50 mph applies the brakes giving the truck a deceleration of 4.5 m/s^2 how long will it take the truck to come to a complete stop what distance will it cover
July 18, 2016

physics
a sports car can accelerate from 0 to 60 mph in 3.2s what is the acceleration of the car in m/s^2 what distance would it travel at this time
July 18, 2016

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