Question

if x +2y=6 then find the value of x³- 8y³ -36xy- 216

Answer 1

let x be 2

x+2y=6

2+2y=6

2y=6-2

y=4/2

y=2

for x^3 -8y^3 -36xy -216

= 8 - 8×8 -36×2×2 -216

= 8 -64 - 36×4 -216

= 8- 64 - 144 -216

= -416