问题 解答题

化简:(1)3a+2-4a-5;(2)2(x2+3)-(5-x2

答案

(1)3a+2-4a-5;

=(3-4)a+2-5,

=-a-3;

(2)2(x2+3)-(5-x2

=2x2+6-5+x2

=(2+1)x2+6-5,

=3x2+1.

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