利用乘法公式计算(x+y)(x²+y²)(x-y)(x的四次方+y四次方)(a-2b+3)(a+2b-3)[(x-y)²+(x+y)²](x²-y²)(m-n-3)²先化简,再求值[(a-1/2)²-(a+1/2)²](a+3),其中a=-2
利用乘法公式计算
(x+y)(x²+y²)(x-y)(x的四次方+y四次方)
(a-2b+3)(a+2b-3)
[(x-y)²+(x+y)²](x²-y²)
(m-n-3)²
先化简,再求值
[(a-1/2)²-(a+1/2)²](a+3),其中a=-2