已知4-x+2y=0,则2x-4y-5的值为
问题描述:
已知4-x+2y=0,则2x-4y-5的值为
答
4-X+2Y=0说明X-2Y=4
2x-4y-5
=2(x-2y)-5
=2*4-5
=3
答
4-x+2y=0
得:x-2y=4
则:2x-4y-5=2(x-2y)-5=2(4)-5=3