试题

题目:
计算或化简:
(1)|-6|+(π-3.14)0-(-
1
3
-1        (2)2-4x5·(23x-22
(3)x(2x-y)-(x+2y)(x-y)        (4)(2m+3n)2·(3n-2m)2
答案
解:(1)|-6|+(π-3.14)0-(-
1
3
-1  
=6+1+3
=10      
(2)2-4x5·(23x-22
=2-4x5·26x-4
=22x
=4x
(3)x(2x-y)-(x+2y)(x-y)
=(2x2-xy)-(x2-xy+2xy-2y2)-(x2-xy+2xy-2y2 )
=x2-2xy+2y2
 (4)(2m+3n)2·(3n-2m)2
=[(2m+3n)·(3n-2m)]2
=(9n2-4m222
=81n4-72m2n2+16m4
解:(1)|-6|+(π-3.14)0-(-
1
3
-1  
=6+1+3
=10      
(2)2-4x5·(23x-22
=2-4x5·26x-4
=22x
=4x
(3)x(2x-y)-(x+2y)(x-y)
=(2x2-xy)-(x2-xy+2xy-2y2)-(x2-xy+2xy-2y2 )
=x2-2xy+2y2
 (4)(2m+3n)2·(3n-2m)2
=[(2m+3n)·(3n-2m)]2
=(9n2-4m222
=81n4-72m2n2+16m4
考点梳理
整式的混合运算;零指数幂;负整数指数幂.
(1)本题须先求出每一部分的值,再把所得的结果相加即可.
(2)本题须先算出乘方,再把所得的结果相加.
(3)本题须先算出两部分的值,再把所得结果合并即可.
(4)本题需根据完全平方公式和平方差公式进行计算.
本题主要考查了整式的混合运算,解题时要注意运算顺序和公式的应用.
计算题.
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