Question

單項(xiàng)式-2x2y，-

1

2

xy2，2x2y，-xy2的和是______．

Answer 1

這4個(gè)單項(xiàng)式的和=-2x²y+（-

1

2

xy²）+2x²y+（-xy²），
=-2x²y-

1

2

xy²+2x²y-xy²，
=-

3

2

xy²．
故答案為：-

3

2

xy²．