Question

if p=2-a then a^3+6ap+p^3-8 is
'

Answer 1

Answer:

p = 2 - a -------( 1 )

LHS = a³ + 6ap + p³ - 8

= a³ + 6a( 2 - a ) + ( 2-a )³ - 8 [ from(1)]

= a³ +12a-6a²+2³-3×2²a+3×2a²-a³-8

= a³ + 12a - 6a² + 8 - 12a + 6a²- a³ - 8

= 0

= RHS

Hence proved.