Question

Find the value of
a³ + b³ – 12ab + 64 , when a + b = – 4

Answer 1

Answer:

Step-by-step explanation:

a³ + b³ – 12ab + 64 , when a + b = – 4

cubing on both sides, (a+b)³=-4³

we get, a³+3a²b+3ab²+b³=-64

a³+b³+3ab(a+b)=-64

as a + b = – 4,

a³+b³+3ab(-4)=-64

a³+b³-12ab+64=0