Friday
August 28, 2015

Posts by STEVE


Total # Posts: 33,101

Algebra
yes. commutative property of multiplication There is also a commutative property of addition, which could be written as (2 + p)(r + 9) = (p + 2)(9 + r)
August 19, 2015

Algebra II
transitive relates 3 values: a=b and b=c ==> a=c Clearly this is just a case of substituting z for y, since y=z.
August 19, 2015

maths
since r is constant, (1-t)/(2-5t) = (t+1)/(1-t) Solve that for t, and you will find that matching sequences are, with r=2 and r=1/3, 1/3, 2/3, 4/3, ... 9/2, 3/2, 1/2, ...
August 19, 2015

physics
Vy = 300-9.8t Vx = 519.6 So, at t=2, Vy = 280.4 Vx = 519.6 |v| = √(280.4^2+519.6^2) = 590.4 θ = arctan(280.4/519.6) = 28.4°
August 19, 2015

Physics
1.07 E = <1.07,0> .533 S = <0,-0.533> 4.62 @ W50.1°N = <-2.963,3.644> add them all up and you have a final displacement of <-1.893,3.111> = 3.642 @ N31.3°W now you can figure the velocity
August 19, 2015

Math
you are correct.
August 19, 2015

Math
well, 1364 = 14*93 + 62 17765 = 27*646 + 323
August 19, 2015

math
y = 3(x-2)^2+3 y' = 6(x-2) y" = 6 critical point is at x=2 minimum because y" > 0 there. http://www.wolframalpha.com/input/?i=3%28x-2%29^2%2B3 But then, you knew all that from Algebra I, right? Vertex of a parabola and all that.
August 19, 2015

math
the domain of rational functions is all reals except where the denominator is zero. x^2+8x+15 = (x+3)(x+5) So, I guess you can work it from there, right?
August 19, 2015

math
If you mean 10sin((x/4)-4π)-5 then that is 10sin((x-16π)/4)-5 period = 2π/(1/4) = 8π shift = 16π
August 19, 2015

Algebra
both right. good work. Of course, your nearest calculator could have confirmed your results...
August 19, 2015

Algebra
10(q-3) + 25q = 1300
August 18, 2015

Diff Calculus
When the water is y meters deep, the surface has a length of 5y and a width of 5. So, its volume is v(y) = 25/2 y^2 dv/dt = 25y dy/dt Now plug in y=1 and dv/dt=0.1 to find dy/dt
August 18, 2015

Math algebr
Looks like A to me.
August 18, 2015

Math dimensional anaylsis
9yd/3hr * 3ft/yd * 1hr/60min = 27/180 = 3/20 ft/min
August 18, 2015

algebra
just replace any x with -1, then simplify: 3(-1)^2-7 3*1-7 6-7 -1 you are correct
August 18, 2015

Calculus
you can always check your answers at wolframalpha.com As you can see, you're way off. If h = 3e^u where u is a function of x, then h' = 3e^u du/dx = 3e^(sin(x+2)) * cos(x+2) http://www.wolframalpha.com/input/?i=derivative+3e^%28sin%28x%2B2%29%29
August 18, 2015

Math
clearly the lines intersect where 1/4 x = -1/4 x 1/2 x = 0 x = 0 so, y=0 Looks like B to me. You can easily check to see that none of the other points lies on either line.
August 18, 2015

Math (Probability)
there are 3 numbers less than 4. So, 3/x = 1/10 ...
August 18, 2015

physics
well, the momentum has changed from 1500*40 to 1500*50 How hard is that?
August 18, 2015

Slope
recall the sloe-intercept form of a line: y = mx+b where m is the slope. slope is defined as the change in y, divided by the change in x. Since y=6x+3, y changes by 6 whenever x changes by 1. For, consider y(x) = 6x+3 y(x+1) = 6(x+1)+3 = 6x+9 x has changed by 1, and y has ...
August 18, 2015

Algebra
if you add the two equations, the x's cancel out, and you have 6y = -12 y = -2 so, x=2. The book answer is wrong. (6,-6) fits the 2nd equation, but not the 1st. If the 1st equation were -4x-2y = -12 then (6,-6) would be correct. So, it appears that the problem has a typo.
August 18, 2015

math sqrt root
x√2x + 2√2x^3 + 2x^2/√2x = x√2x + 2x√2x + x√2x = 4x√2x 2√(2x^3) = √((2x)(x^2)) = 2x√(2x) (2x^2)/√(2x) = = x√(2x)√(2x)/√(2x) = x√2x √(2/3) = √2/√3 = √2/√3...
August 18, 2015

Math (Calculus)
since 3 radians is in QII, sin is positive, and cos is negative. 3 is almost pi: 171.9 degrees
August 18, 2015

Algebra
vertical asymptote is ok horizontal asymptote is at y=1/3 (x^2+2)/(3x^2-5) = (1 + 2/x^2) / (3 - 5/x^2) as x gets huge, the fractions vanish, and we are left with 1/3 When the degree of top and bottom are the same, then the limit is the ratio of the coefficients of the highest ...
August 18, 2015

math
y = ax+bx^2 2a+4b = 14 5a+25b = 65 y = 3x+2x^2 take it.
August 18, 2015

Lyncheez Bee (math)
If the digits are xyz, then x+y+z=9 2y=x+z 2x=z The number is thus 234
August 18, 2015

maths
n=2k+1, so clearly n must be odd. Now, it is also 5k+4, so k must be odd since otherwise 5k is even, and so is n. Any odd multiple of 5 ends in 5, so n must end in 9.
August 18, 2015

maths
2400 is a multiple of 3, so y5 must be a multiple of 3. Can you think of any 2-digit multiples of 3 ending in 5?
August 18, 2015

Algebra
I can see the (a^3)^(1/4) in the denominator, but there's no way to get 648 in the top from what you have written.
August 18, 2015

maths
Do you mean a 4-digit number 91z5? The digits of any multiple of 9 add up to a multiple of 9. So, 9+1+z+5 = 15+z So, z=3 to make the sum 18. 9135 = 9*1015
August 18, 2015

maths
1.94 x 10^2 Not sure just what you're looking for.
August 18, 2015

pre-cal
Remember the law of sines? a/sinA = b/sinB 24/sin42° = b/sin87° Now you can find b with no trouble.
August 18, 2015

maths
Doing my best to parse the wordy and ambiguous notation, I get ((4/3)√3 - 2√2+3)/(3√3 + 2√2) No, that is too weird. How about 4/(3√3-2√2) + 3/(3√3+2√2) Now we can make a common denominator of (3√3-2√2)(3√3+2&#...
August 18, 2015

Math
If x gallons were poured, then (35+x)/(4.5+x) = 7/2 x = 7.7 Now it's easy peasy.
August 18, 2015

algebra
r^3 = 3/192 = 1/64 r = 1/4 So, use that to find x and y Or, you can say (x/192)^2 = 3/x x=48 y/48 = 3/y y=12
August 18, 2015

Math
rev/hr = rev/min * 60min/hr L/rev = L/hr * hr/rev = (L/hr)/(rev/hr) mL/rev = L/rev * 1000mL/L
August 18, 2015

calculus
min/max occur where y'=0 So, just solve 4x^3-12x^2+8x=0 So, which are min and which max? Minimum if y" > 0 (concave up) Maximum if y" < 0 (concave down) So, take a look at y" = 4(3x^2-6x+2)
August 18, 2015

math 5
I didn't see a question, but your response seems like a reasonable answer.
August 18, 2015

Math
R=xxx clearly the 1st digit is 0 or 5, so it must be 5, since 3-digit numbers don't usually start with 0. R=1x5 The second and third digits add to 8 R=135 The last item is redundant.
August 18, 2015

maths - incomplete
did you forget the interest rate? The principal?
August 17, 2015

Algebra
That would be ∜(8/9a^3) Not sure what you mean by simplify. You could break it into separate factors, but There aren't any 4th-powers to factor out of the radical.
August 17, 2015

math
The angles are 5x,6x,7x and they add to 180. So, 18x = 180, x=10, and the angles are 50,60,70 So what do you think?
August 17, 2015

math
check your distance formula. It is √((5-(-3))^2+(-5-1)^2) = √(8^2+6^2) = √100 = 10
August 17, 2015

math grade 12
.75 * .75
August 17, 2015

math grade 12
Add up all the points. You need x where 85+89+x >= 3*90
August 17, 2015

Math
much better!
August 17, 2015

Math
How ever did you come up with that answer? You have 5a, and you want a by itself. How do you get rid of the 5? Recall that 5/5 = 1
August 17, 2015

Math using symbols
you are correct on both of them. Good work.
August 17, 2015

Math using symbols
you have 2 rows, each with 3+4 stars So, what do you think? Hint: distributive property In #2, there is no multiplication, just 3+4+5 stars So, what do you think? Hint: associative property
August 17, 2015

Math
Nope. Inequalities do not have a single value for a solution. -3 < 2x+1 < 5 -4 < 2x < 4 -2 < x < 2 Clearly 4 does not work. 2*4+1 is not less than 5. Any value between -2 and 2 will work.
August 17, 2015

Math
so am I. All I can do is use what you wrote, which doesn't make a lot of sense to me. How about you try posting the real question? |1| = 1 |11| = 11 Other than that, I have no help to give at this point.
August 17, 2015

Math
That would be _____+10
August 17, 2015

algebra 2
If you are trying to find the determinant such that |0 0 -1| |3 x 0| = x^2 |2 0 3| Then that reduces to 2x = x^2
August 17, 2015

math help
It is C if you meant 5*2x^2 Try not to confuse x (the variable) with x (multiplication) Use * to multiply ^ for powers
August 17, 2015

Algebra
domain is all reals except where the denominator is zero So, if you have 1/(x-1)^2 - 5 D= all reals except x=1 Clearly, 1/(x-1)^2 is smallest when x is huge. Then it is close to zero, but always a little bit positive. So, R= all reals y > -5
August 17, 2015

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

  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