问题
解答题
计算:(1)2×(-3)2-5÷
(2)7a2b+(-4a2b+5ab2)-(2a2b-3ab2) |
答案
(1)2×(-3)2-5÷
×2,1 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.
计算:(1)2×(-3)2-5÷
(2)7a2b+(-4a2b+5ab2)-(2a2b-3ab2) |
(1)2×(-3)2-5÷
×2,1 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.