若2x-3y/x+y=1/2,求x/y (2)若a+b/b=6/5,求a/b,a-b/b (3)如果x/2=y/3=z/4不等于0,求x-y+3z/3x-y的值
问题描述:
若2x-3y/x+y=1/2,求x/y (2)若a+b/b=6/5,求a/b,a-b/b (3)如果x/2=y/3=z/4不等于0,求x-y+3z/3x-y的值
都要有具体过程
答
(1)2x-3y/x+y=1/2
x+y=4x-6y
7y=3x
x/y=7/3
(2)a+b/b=6/5
6b=5a+5b
b=5a
a/b=1/5
把b=5a代入a-b/b
得原式=a-5a/5a=-4/5
(3)x/2=y/3=z/4
设x=2k,y=3k,z=4k
原式=2k-3k+12k/6k-3k=11/3