Question

Find the value of a3 + 8b3 , if a +2b = 10 and ab = 15.

Answer 1

a+2b=10
cubing both sides
(a+2b)^3=(10)^3
$a ^{3} + 8b ^{3} + 3(a)(2b)[a+2b] = 1000$
$a ^{3} + 8b ^{3} + 3(15)(10)= 1000$
$a ^{3} + 8b ^{3} = 700$

Answer 2

Answer:

10a²-150+40b²

Step-by-step explanation:

by this identity we can solve

a³+b³=(a-b)(a²+ab+b²)