先化简,再求值:(x+1)²-(x-2)(x+2),其中X=-3

2024-12-25 19:13:48
推荐回答(4个)
回答1:

原式=x²+2x+1-x²+4=2x+5
当x=-3时,原式=-6+5=-1

回答2:

:(x+1)²-(x-2)(x+2),
=x²+1+2x-x²+4
=2x+5
=2*(-3)+5
=-1

回答3:

:(x+1)²-(x-2)(x+2),
=x²+2x+1-x²+4
=2x+5
=-6+5
=-1

回答4:

原式=2x+5=-1