计算或化简求值 (1)(1/4a2b)•(−2ab2)2÷(−0.5a4b5) (2)4x2-(-2x+3)(-2x-3) (3)20102-2009×2011 (4)(a-2b+c)(a+2b-c) (5)[(x+y)2-(x+y)(x+
计算或化简求值
(1)
(a2b)•(−2ab2)2÷(−0.5a4b5)(2)4x
2-(-2x+3)(-2x-3)
(3)2010
2-2009×2011
(4)(a-2b+c)(a+2b-c)
(5)[(x+y)
2-(x+y)(x+3y)-5y
2]÷(2y),其中x=-2,y=
.
数学人气:648 ℃时间:2019-08-22 11:50:15
优质解答
(1)原式=
a
2b•4a
2b
4÷(-0.5a
4b
5)=-2;
(2)原式=4x
2-(4x
2-9)=9;
(3)原式=2010
2-(2010-1)×(2010+1)=2010
2-(2010
2-1)=1;
(4)原式=a
2-(2b-c)
2=a
2-4b
2+4bc-c
2;
(5)(x
2+2xy+y
2-x
2-3xy-xy-3y
2-5y
2)÷(2y)=(-7y
2-2xy)÷(2y)=-
y-x,
当x=-2,y=
时,原式=
.
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