问题 解答题

计算:(1)(5a2+2a)-4(2+2a2);

(2)5x2(x+1)(x-1).

答案

(1)(5a2+2a)-4(2+2a2),

=5a2+2a-8-8a2

=-3a2+2a-8;

(2)5x2(x+1)(x-1),

=5x2(x2-1),

=5x4-5x2

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