(1) 解不等式 3(x+2)-1≥6-2(x-2) (2) 先化简,再求值:2(x+1)(x-1)-x(2x-1),其中x =-2

2024-12-03 16:05:49
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回答1:

解:(1)3x+6-1≥6-2x+4 
3x+2x≥6+4-6+1
5x≥5 
x≥1
(2)原式=2x 2 -2-2x 2 +x 
=x-2 
当x=-2时,原式=-2-2=-4 
(3)原式=3x(x 2 -4y 2
=3x(x+2y)(x-2y)