若4x-3y=0且x和y不等零,则4x-5y/4x=5y的值为( ) A.1/31 B.31 C.-1/4 D.32
问题描述:
若4x-3y=0且x和y不等零,则4x-5y/4x=5y的值为( ) A.1/31 B.31 C.-1/4 D.32
答
是求4x-5y/4x+5y吧是的话选C
4x-3y=0
4x=3y
所以
原式=4x-5y/4x+5y
=(3y-5y)/(3y+5y)
=-2y/8y
=-1/4