问题
解答题
计算: (1)
(2)2
(3)3ab(2a2b-ab2); (4)(3a-b)(-b+4a); (5)(-2x+y)2+4y(x-
(6)(-2a+b)(-2a-b)+2a(-3a+
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答案
(1)
+4
-(-4)2
;3 -27
=2+4-(-3)
=9;
(2)2
+(-1)3-2×2
-(2 2
-2)03
=2
-1-2
-12
=
-2;2
(3)3ab(2a2b-ab2)
=6a3b2-3a2b3;
(4)(3a-b)(-b+4a)
=-3ab+12a2+b2-4ab
=12a2-7ab+b2;
(5)(-2x+y)2+4y(x-
y)1 2
=4x2-4xy+y2+4xy-2y2
=4x2-y2;
(6)(-2a+b)(-2a-b)+2a(-3a+
ab)1 2
=4a2-b2-6a2+a2b
=-2a2-b2+a2b.