先化简,再求值:(1-4y)(1+4y)+(1+4y)²,其中y=2/8.
问题描述:
先化简,再求值:(1-4y)(1+4y)+(1+4y)²,其中y=2/8.
答
(1-4y)(1+4y)+(1+4y)²
=(1+4y)(1-4y+1+4y)
=2(1+4y)
=2+8y
=2+8×2/8
=2+2
=4