题目内容
一个多项式减去x2-2y2等于x2+y2,则这个多项式是( )
| A.-2x2+y2 | B.2x2-y2 | C.x2-2y2 | D.-x2+2y2 |
多项式为:x2-2y2+(x2+y2)
=(1+1)x2+(-2+1)y2
=2x2-y2,
故选B.
=(1+1)x2+(-2+1)y2
=2x2-y2,
故选B.
练习册系列答案
相关题目
题目内容
| A.-2x2+y2 | B.2x2-y2 | C.x2-2y2 | D.-x2+2y2 |