问题
计算题
化简: (1)5a﹣(2a﹣4b);
(2)5(3a2b﹣ab2)﹣4(﹣ab2+3a2b).
答案
解:(1)5a﹣(2a﹣4b)
=5a﹣2a+4b
=3a+4b;
(2)5(3a2b﹣ab2)﹣4(﹣ab2+3a2b)
=15a2b﹣5ab2+4a2b﹣12ab2
=(15﹣12)a2b+(﹣5+4)ab2
=3a2b﹣ab2.
化简: (1)5a﹣(2a﹣4b);
(2)5(3a2b﹣ab2)﹣4(﹣ab2+3a2b).
解:(1)5a﹣(2a﹣4b)
=5a﹣2a+4b
=3a+4b;
(2)5(3a2b﹣ab2)﹣4(﹣ab2+3a2b)
=15a2b﹣5ab2+4a2b﹣12ab2
=(15﹣12)a2b+(﹣5+4)ab2
=3a2b﹣ab2.