Question

If (4a+3b)=10 and ab=2 find the value of 64a^3 + 27b^3

Answer 1

(4a+3b)^3 = (4a)^3 + (3b)^3 + 3×4a×3b(4a+3b)

(10)^3 = 64a^3 + 27b^3 + 36×2×10

1000 = 64a^3 + 27b^3 + 720

1000-720=64a^3 + 27b^3

280 = 64a^3 + 26b^3