计算:8/9(x+2)(x+2)-2(y-1)(y-1),
问题描述:
计算:8/9(x+2)(x+2)-2(y-1)(y-1),
答
8/9(x+2)(x+2)-2(y-1)(y-1)
=8/9(x²-4)-2(y²-1)
=8/9x²-32/9-2y²+2
=8/9x²-2y²-14/9