已知x/y=3/4,求2x-y/x+y的值.
问题描述:
已知x/y=3/4,求2x-y/x+y的值.
答
y=4x/3
所以(2x-y)/(x+y)
=(2x-4x/3)/(x+4x/3)
=(2x/3)/(7x/3)
=2/7