Question

Sa se calculeze:
a) (2√2-3a) (2√2+3a)
b)(x supra 3 +2y)³

Answer 1

a) (2√2-3a) (2√2+3a) =8-9a²
formula (a+b)(a-b)=a²-b²

b)(x/3 +2y)³ =
=x³/27+ 3*x²/9*2y+3*x/3*4y²+8y³=
=x³/27+ 2x²y/3+4xy²+8y³
formula (a+b)³=a³+3a²b+3ab²+b³