Question

已知:x-2y=-3,则(2y-x)-2x+4y-1的值为

Answer 1

(2y-x)-2x+4y-1
=-（x-2y）-2(x-2y)+1
=3+2x3+1
=10

追问

遇到相似的怎么做？麻烦一下

Answer 2

(2y-x)-2x+4y-1
=-（扮档中x-2y）厅山蠢余-2(x-2y)+1
=-3(x-2y)+1
=-3*(-3)+1
=9+1
=10