先化简,再求值:2b+(a+b)(a-b)-(a-b)눀,其中a等于-3,b等于二分之一

2024-12-30 15:50:58
推荐回答(2个)
回答1:

2b+(a+b)(a-b)-(a-b)²
=2b+a²-b²-a²+2ab-b²
=2b+2ab-2b²
=2b(1+a-b)
=2×1/2×(1-3-1/2)
=-2.5

回答2: