问题 解答题

化简

(1)(-2y23+y-y5

(2)(x+2)2-(x+1)(x-1)

答案

(1)(-2y23+y•y5

=-8y6+y6

=-7y6

(2)(x+2)2-(x+1)(x-1)

=x2+4x+4-x2+1

=4x+5.

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