问题
解答题
计算:
(1)5s2t-2s2t;
(2)-22+20-|-3|×(-3)-1;
(3)(a2b)(-2ab2)(-0.5a4b5);
(4)4m2-(-2m+3)(-2m-3).
答案
(1)原式=(5-2)s2t
=3s2t;
(2)原式=-4+1-3×(-
)1 3
=-4+1+1
=-2;
(3)原式=(-2)×(-0.5)a7b8
=a7b8;
(4)原式=4m2-(-2m)2+9
=9.