计算:(1-y)²-(1+y)(1-y)
问题描述:
计算:(1-y)²-(1+y)(1-y)
答
原式=1²-2y+y²-(1²-y²)
=2y²-2y
计算:(1-y)²-(1+y)(1-y)
原式=1²-2y+y²-(1²-y²)
=2y²-2y