rút gọn : (x+3)^2 + 2(x+3)(x-3) +(x-3)^2 03/07/2021 Bởi Harper rút gọn : (x+3)^2 + 2(x+3)(x-3) +(x-3)^2
$(x+3)^2 + 2(x+3)(x-3) +(x-3)^2$
$⇒[(x+3)+(x-3)]^2$
$⇒(x+3+x-3)^2$
$⇒(2x)^2$
$⇒4x^2$
Đáp án:
`(x+3)^2+2(x+3)(x-3)+(x-3)^2`
`=(x+3+x-3)^2`
`=(2x)^2=4x^2`