若2x-y=3,试求-5-4x+2y的值
来源:百度知道 编辑:UC知道 时间:2024/06/02 19:43:29
值为-11
因为2x-y=3
所以y=-3+2x
带入-5-4x+2y
得:-5-4x+2*(-3+2x)
=-5-4x-6+4x
=-11
若2x-y=3,
-5-4x+2y
=-5-(4x-2y)
=-5-2×(2x-y)
=-5-2×3
=-11
-5-4x+2y
=-5-2(2x-y)
=-5-2*3
=-11
-5-4x+2y=-5-(4x-2y)=-5-2(2x-y)=-5-2*3=-11
-5-4x+2y=-5-2(2x-y)
将2x-y=3代入上式得
-5-2*3=-11
-11
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