问题 解答题

化简:

(1)9a+7a-6a

(2)(3a2-b2)-3(a2-2b2

答案

(1)9a+7a-6a

=16a-6a

=10a;

(2)(3a2-b2)-3(a2-2b2

=3a2-b2-3a2+6b2

=5b2

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