Question

(2x-y)² ;(4+2x)²;
(2√2-3a)(2√2+3a)

Answer 1

$a).(2x-y)^2=(2x)^2-2 \cdot 2x \cdot y+y^2=4x^2-4xy+y^2 \\ b).(4+2x)^2=4^2+2 \cdot 4 \cdot 2x+(2x)^2=16+16x+4x^2 \\ c).(2 \sqrt{2} -3a)(2 \sqrt{2}+3a)= 8-9a^2$