SOLUTION: Find the Value of: a^3 + 8b^3 if a + 2b = 10 and ab= 15 Hint: (a+2b)^3 = a^3 + 8b^3 + 6ab(a+2b) = a^3+8b^3 = (a+2b)^3 - 6ab(a+2b)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Find the Value of: a^3 + 8b^3 if a + 2b = 10 and ab= 15 Hint: (a+2b)^3 = a^3 + 8b^3 + 6ab(a+2b) = a^3+8b^3 = (a+2b)^3 - 6ab(a+2b)       Log On


   

Question 1092355: Find the Value of:
a^3 + 8b^3 if a + 2b = 10 and ab= 15
Hint: (a+2b)^3 = a^3 + 8b^3 + 6ab(a+2b)
= a^3+8b^3 = (a+2b)^3 - 6ab(a+2b)

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!

Use the hint they gave you.... If
%28a%2B2b%29%5E3+=+a%5E3+%2B+8b%5E3+%2B+6ab%28a%2B2b%29 then the expression you are to evaluate is
a%5E3+%2B+8b%5E3+=+%28a%2B2b%29%5E3+-+6ab%28a%2B2b%29

You are given the values of both (a+2b) and (ab) -- plug them into that equation and evaluate.