问题
解答题
计算题: (1)(-
(2)(a+b)2-2a(b+1)-a2b÷b (3)5ab2-{2a2b-[3a2b-ab(b-2a) (4)解方程:(x-2)2-4=0. |
答案
(1)原式=
+1 4
-1+11 2
=
;3 4
(2)原式=a2+2ab+b2-2ab-2a-a2
=b2-2a;
(3)原式=5ab2-{[2a2b-(3a2b-(ab2-2a2b)÷(-
ab)}1 2
=5ab2-[2a2b-(3a2b+2b-4a)]
=5ab2-(2a2b-3a2b-2b+4a)
=5ab2-2a2b+3a2b+2b-4a
=5ab2+a2b+2b-4a;
(4)(x-2)2-4=0,
变形得:(x-2)2=4,
开方得:x-2=2或x-2=-2,
解得:x1=4,x2=0.