Wednesday
September 2, 2015

Posts by steve


Total # Posts: 33,245

Algebra
If there are x vials of A, then then the rest (60-x) are of B. So, adding up the costs, we have 39.95x + 30.34(60-x) = 2022.21 Now just solve for x and then figure 60-x.
August 17, 2015

kogi state university
If there are n to choose from, then that is P(n,5) or C(n,5)
August 17, 2015

math
168 @ 43.5° = <115.6,121.9> 33 @ 133.5° = <23.94,-22.72> add up the x- and y-components and the resultant velocity is <139.54,99.18> = 171.20 @ 54.6°
August 17, 2015

chemistry
assuming STP for the O2, you have 5.6/22.4 = 0.25 moles O2 5.6g = 5.6/55.85 = 0.10 moles Fe If your reaction is 4Fe + 3O2 = 2Fe2O3 then the reaction consumes elements in the ratio (moles O2)/(moles Fe) = 3/4 Your available reagents are in the ratio of O2/Fe = 0.25/0.10 = 5/2 ...
August 17, 2015

mathematics
I cannot interpret all those words. What is "by" supposed to mean? Is 3 to power 5by2 2*3^5 or (3^5)^2 That is, does by mean multiply by or raise to a new power? Try using * for multiply ^ for exponent () to make it clear what is grouped Ahhh. I think the "by&...
August 17, 2015

uniuyo
the 5th terms is the 3rd after the 2nd term, so their ratio is r^3. Thus, r^3 = 567/21 = 27 r = 3 a = 21/3 = 7
August 17, 2015

word problem
x+y = 38 8+2x = 5y Now just solve for x and y
August 17, 2015

Math
Just read what they say and start filling in the digits! I am a four digit number xxxx I am between 2,000 and 3,000 2xxx the digit in the ones place is four times as much as the digit in the thousands place 2xx8 Only one of the digits are the same. Ya got me what that means. ...
August 17, 2015

bogus
42
August 17, 2015

Precalculus
Since the ratio of radius/height is constant at any water depth (45/6 when full), r = 15/2 h. You want h when v=5000. v = 1/3 πr^2 h, so π/3 (15/2 h)^2 h = 5000 π/3 * 225/4 h^3 = 5000 h^3 = 12*5000/225 = 800/3 h = 6.43m
August 16, 2015

Physics
conserve momentum: .050v + 7.00(0) = 5.00(.050+7.00) v = 705 m/s
August 16, 2015

word problems
x+y = 38 8+2x = 5y Now just solve for x and y.
August 16, 2015

math
with y being the number of tires produced per hour, y = 50 + 10x
August 16, 2015

king george memorial school math
assuming base 10, we have log(x) + log(y) = 4 log(xy) = 4 xy = 10^4 = 10000 y = 10000/x
August 16, 2015

Physics
since v = 4/3 πr^3, then the density (mass/volume) is 8.1*10^28kg / (4/3 π*(1.7*10^3)^3)m^3 = 3.936*10^18 kg/m^3 3.936*10^18 kg/m^3 * 2.0*10^-7 m^3 = 7.872*10^11 kg mass = density*volume You divided, and even did that wrong.
August 16, 2015

Maths- calculus
The length of the kit string is z(t). We have z^2 = 40^2 + (x-k)^2 x' = 1 z' = 1 At the moment in question, x-k = 30, so z=50 2z z' = 2(x-k)(x'-k') 100 = 60(1 - k') 5/3 = 1 - k' k' = -2/3 Seems odd, doesn't it? But a little consideration ...
August 16, 2015

algebra
well, I guess you also have to add f >= 0 c >= 0
August 16, 2015

algebra
If there are f lbs of fish and c lbs of chicken, then 11 <= 4f+3c <= 15
August 16, 2015

math
no, the price depends on the other factors. All of the others are independent, since they can vary on their own.
August 16, 2015

trigonometry
Draw a diagram. If the pole has height h, then h = 21/(cot58°-cot67°) = 104.8 The two wires have length 104.8 csc67° = 113.9 104.8 csc58° = 123.6
August 16, 2015

physics
(a)since time=distance/speed, you have total distance: 73.2+73.2=146.4m total time: 73.2/1.2 + 73.2/3.1 = 84.6s avg speed: 146.4m/84.6s = 1.73 m/s do (b) the same way
August 16, 2015

math
to avoid having to use Greek letters, I'll just use x. I think you mean z = cos(x) + j sin(x) De Moivre's formula says that z^n + 1/z^n = z^n + z^-n = cos(nx) + j sin(nx) + cos(-nx) + j sin(-nx) = cos(nx) + j sin(nx) + cos(nx) - j sin(nx) = 2cos(nx) cos(x) is a ...
August 16, 2015

Algebra
x^2 * x^n x^(2+n) x^3 * x^n = x^(3+n) now, after the division, subtracting powers, you have x^((2+n)-(3+n)) = x^-1 = 1/x You can see that this is so, because in the original fraction, you can cancel the x^n factors, leaving just x^2/x^3 = 1/x
August 15, 2015

Algebra
better is |x-(-10)| >= 6 or |x+10| >= 6
August 15, 2015

Algebra
this is the sum of two cubes: (x^n)^3 + (y^n)^3 (x^n + y^n)(x^2n - x^n y^n + y^2n)
August 15, 2015

Calculus
1/(x+2) - 1/2 = (2-(x+2)) / 2(x+2) = -x/(2(x+2)) Now divide that by x, and you are left with -1/(2(x+2)) -> -1/4 You can divide by x, because until you take the limit, x is not zero.
August 15, 2015

Algebra
x^3 (3)(x^2+1)^2 (2x)+(x^2+1)^3 (3x^2) 6x^4(x^2+1)^2 + 3x^2(x^2+1)^3 3x^2(x^2+1)^2 (2x^2+x^2+1) 3x^2(x^2+1)^2 (3x^2+1)
August 15, 2015

Algebra
x^4(4) (2x+1)^3 (2x)+(2x+1)^4 (4x^3) Collecting factors, we have 8x^5(2x+1)^3 + 4x^3(2x+1)^4 = 4x^3(2x+1)^3 (2x^2+2x+1)
August 15, 2015

Alg 2
Just use the coefficients of Pascal's Triangle, and plug and chug: ((6-a)x)^12 + 12((6-a)x)^11(ay) + ... See it in all its glory at http://www.wolframalpha.com/input/?i=[%286-a%29x%2Bay]^12 This is one of those problems that are really pointless. Asking for the 12th power ...
August 15, 2015

Alg 2
r^3 = (1/5)/25 = 1/125 so, r = 1/5 An = 5*(1/5)^(n-1) = 125/5^n S8 = 25(1 - (1/5)^8)/(1 - 1/5) = 97656/3125
August 15, 2015

Math
a1 = 2 a2 = 3a1-1 = 3*2-1 = 5 a3 = 3a2-1 = 3*5-1 = 14 and so on
August 15, 2015

Math Check
proof by induction
August 15, 2015

Math Check
A little research will turn up many proofs that A(n) = n(n+1)/2 One easy way is to divide the numbers into pairs, from both ends. 1,n 2,n-1 3,n-2 ... Each pair adds up to n+1 There are n/2 such pairs. The result follows.
August 15, 2015

Biology
thank you
August 15, 2015

Biology
How is a protein different from a complex carbohydrate? a.The monomers that make up a protein vary whereas the monomers that make up a complex carbohydrate are all the same. b.Proteins function as energy storage polymers whereas complex carbohydrates function to control rates ...
August 15, 2015

Math
no idea. What shape is the container? Do the marbles touch all of the nearest sides of the container? Only one side? Any sides at all? Lots of specifics left out here.
August 15, 2015

pre-algebra
4/5 x + 5 < -3 4/5 x < -8 4x < -40 x < -10
August 15, 2015

math
clearly the black tea is 1/4 of the total The price p is thus 10(2.40)+30(3.20) = 40p
August 15, 2015

lasmocol
figure the number of moles of the silver compound. Since 500cm^3 is 0.5 liters, the molarity is twice the # of moles.
August 15, 2015

Urgent math
the expansion of (a+b)^10 starts out with a^10, so the term with a^3 is C(10,7)a^3b^7 So, since you have a = 3x and b = -3, that would be C(10,7)(3x)^3(-3)^7 = 360(27x^3)(-2187) = -7085880x^3
August 15, 2015

Urgent math
the common difference is d=5 So, the nth term is 4 + 5(n-1) or, 5n-1
August 15, 2015

Algebra ASAP
an = 0.85 * 1.29^n Now just plug in n=6
August 15, 2015

Math
No way to tell. What size cake did those ingredients make?
August 14, 2015

AHOOOGAAH! HOMEWORK DUMP!
So many questions! So little work to show! This is what is affectionately known as a Homework Dump.
August 14, 2015

Algebra 1
If 5% is gone, that leaves 95% of the previous population. So, #3.
August 14, 2015

Algebra 1 - eh?
eh?
August 14, 2015

math
(x+y)(x-y) = 105 Since 105 = 3*5*7, I suspect that x-y is one of those values. Now, 105 = 3*35 or 5*21 or 7*15 So, we can try x-y=3 x+y=35 (x,y) = (19,16) x-y=5 x+y=21 (x,y) = (13,8) x-y=7 x+y=15 (x,y) = (11,4)
August 14, 2015

Geometry
Wouldn't it be x-30+x+76=180 2x+46=180 2x=134 x=67 thus 67-30=37 and 67+76=143
August 14, 2015

Geometry
<1 &<2 are a linear pair. m<1=x-30 & m<2=x=76. Find the measure of each angle.
August 14, 2015

Geometry
That would makem it 24 + 34 =58 T NMO = 6(24)-28 58 + nmo = 144 - 28 = 119 116- 58 = 58 Thank you
August 14, 2015

Geometry
Line MO bisects <LMN, m<LMN =6x-28,m<LMO=x+34. Find m<NMO
August 14, 2015

Math
4/3 the speed means 3/4 the time. time = distance/speed
August 14, 2015

math
starting with x, .05x on rent, leaving .95x .95x * .20 = .19x on car, leaving .76x of the remainder, 7/20 = 4907, so 13/20 = 9113 So, 9113+4907 = .76x x = 18447.37
August 14, 2015

Geometry
50
August 14, 2015

Geometry
since BD bisects the angle, we must have] 5x = 3x+10 2x = 10 x = 5 So, you are correct, but that does not answer the question: What is <ABC?
August 14, 2015

Geometry
sorry = my answer is 5
August 14, 2015

Geometry
Find the,<ABC if the line BD bisects <ABC and given m<ABD = 5x and m<DBC = 3x + 10.
August 14, 2015

math
since time=distance/speed, x/5 + 1/2 + x/(5/2) = 4 x = 35/6 His total distance is 2x
August 14, 2015

math
net inflow is 4 - 1/2 = 7/2 gal/min So, it takes 50/(7/2) = 14.3 min to fill
August 14, 2015

Calculus
Since x has degree less than x^2-100, the horizontal asymptote is y=0 since x^2-100 = 0 at x = ±10, and x≠0, those are the vertical asymptotes I find the function unrealistic. It implies negative concentrations, going off the charts as time increases. I suspect a ...
August 14, 2015

Math
x - x/5 - 2x/3 = 60 x(1 - 1/5 - 2/3) = 60 x(15-3-10)/15 = 60 x(2/15) = 60 x = 60(15/2) = 450
August 14, 2015

college algebra
Assuming you mean 3^(1-x) = 1/27 3^(1-x) = 3^(-3) 1-x = -3 x = 4
August 14, 2015

algebra 2
1st digit: 1-9 other digits: 0-9 So, 9*10*10*10 = 9000 possibilities
August 14, 2015

Algebra ASAP
find r by dividing any term by the previous term: r = 9/36 = 1/4 So, Tn = 36*(1/4)^(n-1) = 144/4^n T10 = 144/4^10 This was pretty straightforward. Looks like you need to review the topic.
August 14, 2015

Algebra
If the shorter list has x items, then x + x+7 = 33
August 13, 2015

algebra
5ac+10ab-25ad = 5a(c+2b-5d) 4x(a+b)-3y(a+b) = (4x-3y)(a+b) ax-bx+2a-2b = x(a-b)+2(a-b) = (x+2)(a-b) 2(x+y)-t(x+y) = (2-t)(x+y) These are pretty straightforward. Look how they worked out, and try some more on your own. It just takes a little practice to get used to seeing the ...
August 13, 2015

physics
see related questions below.
August 13, 2015

calc
clearly that would be ∫[0,2] t^2-1 dt = 2/3 But that is the algebraic distance (final displacement), since it starts out with negative velocity. To get the actual distance traveled, you need to separate the two parts: ∫[0,1] -(t^2-1) dt + ∫[1,2] t^2-1 dt = 2/...
August 13, 2015

Math
you are correct.
August 13, 2015

Math
Looks like you need to study what 50% more efficient means. It means B can do 50% more work than A in a given time. 50% = 0.5 So, 50% more means 1.5 times as much. That's 3/2. Think about it. If I do twice as much as you, it takes half (1/2) as long. If I do 3/2 as much as...
August 13, 2015

Math
3/2 as productive means it takes 2/3 as much time. So, (D).
August 13, 2015

Math
-4 = 0-4, but -1 ≠ 5-4
August 13, 2015

Math
Doesn't look like it, assuming I have read your garbled text correctly.
August 13, 2015

Math Urgent
well, let's see what happens. 12 6 3 10 5 16 8 4 2 1 4 2 1 4 2 1 tarting with T8, they repeat with a period of 3 1000 = 7+993 = 7+3*331 So, T1000 = 1
August 13, 2015

STATISTICS
looks like 0.12^3 to me.
August 13, 2015

Math Probability
clearly one step will take the ant to the equator of the octahedron. From there, there are 4 ways to go, only one of which continues on to the bottom. So, p = 1/4
August 13, 2015

English
thank you
August 13, 2015

English
Id the 2 adjectives. Argyles are patterned socks named after a Scottish clan. My answer patterned & Scottish
August 13, 2015

Sociology
thank you
August 13, 2015

Sociology
Understanding what is required to test theories? a- reason b- imagination c- validity research my answer is d
August 13, 2015

math
(6*42)/36 = 7
August 13, 2015

Applied Geometry
The area of an equilateral triangle with sides of 3 is 1/4 * 3^2 * √3 So, the volume of the pyramid is 1/3 (9√3/4)(4) = 3√3 = 5.2 You are correct.
August 13, 2015

Geometry
Nope. The whole circumference is 2πr = 16π
August 13, 2015

Maths
ok. now what?
August 13, 2015

Maths
do you mean 4√(132/143) - 2 or ∜(132/143) - 2 Not sure what "by" means here. Either way, there's not much that can be simplified. 132/143 = 11*12 / 11*13 = 12/13
August 13, 2015

maths
s/3 + 3t/4 = 30.5 2t = 6(j-s) j=34 solve that and you have s=24 t=30
August 13, 2015

Math
Just write down in symbols what they told you. If there are a apples and p pears, then a+p = 450 (1/2)a + (3/4)p = 265 a=290 p=160 a-p = 130
August 13, 2015

math
Which ways can two of the 15 coupons total $10? 2+8 5+5 8+2 P(2,8) = 5/15 * 2/14 = 1/21 P(5,5) = 2/15 * 1/14 = 1/105 P(8,2) = 2/15 * 5/14 = 1/21 Add up the ways and you get 11/105
August 13, 2015

math
20*15*6.00 = ?
August 13, 2015

Arithmetic progession
a+2d = 10(a+d) a+6d = 7a Solve for a and d, and then you can find the sum of T8+T15 = (a+7d)+(a+14d)
August 13, 2015

MATH
well, since there are 360° for 24 hours, every hour is 15° of longitude. The latitude does not matter.
August 13, 2015

Urgent math
well, finding the first six terms is easy, right? An = 5n^2-1, so here's a table: n An 1 5*1^2-1 = 5-1 = 4 2 5*2^2-2 = 20-2 = 18 3 5*3^2-3 = 45-3 = 42 4 5*4^2-4 = 80-4 = 76 5 5*5^2-5 = 125-5 = 120 6 5*6^2-6 = 180-6 = 174 Now just add 'em up to get S6
August 12, 2015

Calculus
just to get rid of pesky decimals. Fractions are exact; decimals can often be only an approximation, as in 2/3 = 0.666...
August 12, 2015

Math
If there were c correct answers, then there were 10-c wrong answers. So, now use her score to find c: 5c - 2(10-c) = 29
August 12, 2015

Math (Calculus)
you need both the product rule and the chain rule. f(x) = (3x)(x^2+4)^-1 f'(x) = (3)(x^2+4)^-1 + (3x)(-1)(x^2+4)^-2(2x) = 3/(x^2+4) - 6x^2/(x^2+4)^2 = (3(x^2+4)-6x^2)/(x^2+4)^2 = (12-3x^2)/(x^2+4)^2 The quotient rule produces the same result; in fact, you can see the ...
August 12, 2015

math
time of truck: 15:24-12:00 = 204 minutes time of flight: 3:24-1:48 = 96 minutes So, if the truck's speed was x km/hr, we have (x km/hr)(204 min) = (170 km/hr)(96 min) x = 170*96/204 = 80 You could convert everything to m/s, or use fractional hours or something, but if you ...
August 12, 2015

Math
If you google images for "ruler" you will find many images. Some have an inch divided into 16 parts, and some into only 8 parts. If you remember that 1/8 = 2/16, you should have no trouble getting what you want.
August 12, 2015

Geometry
If BC=2y and CD=2x, note that triangles ADF, ECF, and ABE are all right triangles with one leg half of a side of the rectangle. We know that ABCD has area (2x)(2y) = 72, so xy=18. ADF has area (2y)(x)/2 = xy = 18 ECF has area (y)(x)/2 = xy/2 = 9 ABE has area (y)(2x)/2 = xy = ...
August 12, 2015

Algebra
If there were c correct answers, then there were 10-c wrong answers. So, now use her score to find c: 5c - 2(10-c) = 29
August 12, 2015

alegebra
AP: T1 = a T3 = a+2d T9 = a+8d GP: T1 = a T2 = ar T3 = ar^2 a+6d = 14 a+2d = ar a+8d = ar^2 Solve all that and you find a=2 d=2 r=3 T20 of the AP is 2+19*2 = 40 Check: AP: 2 4 6 8 10 12 14 16 18 20 ... GP: 2 6 18 ...
August 12, 2015

  1. Pages:
  2. <<Prev
  3. 1
  4. 2
  5. 3
  6. 4
  7. 5
  8. 6
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. 14
  17. 15
  18. Next>>

Members