Question

if 4x-5z=16 & xz=12,find 64x^3-125z^3​

Answer 1

Explanation:

Given,

$4x - 5z = 16$

$xz = 12$

$({4x - 5z})^{3} = 16^{3}$

$64 {x}^{3} - 125 {z}^{3} - 3(4x)(5z)(4x - 5z) = 4096$

$64x ^{3} - 125z^{3} - 60xz(4x - 5z) = 4096$

$64x^{3} - 125z^{3} - 60(12)(16) = 4096$

$64x^{3} - 125z^{3} = 4096 + 11520 = 15616$

Answer: 64x^3 - 125z^3 = 15616