问题 解答题
计算:(1)2×(-3)2-5÷
1
2
×2

(2)7a2b+(-4a2b+5ab2)-(2a2b-3ab2
答案

(1)2×(-3)2-5÷

1
2
×2,

=2×9-5×2×2,

=18-20,

=-2;

(2)7a2b+(-4a2b+5ab2)-(2a2b-3ab2),

=7a2b-4a2b+5ab2-2a2b+3ab2

=(7-4-2)a2b+(5+3)ab2

=a2b+8ab2

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