Question

x、y满足 |2x-y+1|+2根号(3x-2y+4)=0 ,

Answer 1

绝对值和算术平方根大于等于0,相加等于0,若有一个大于0,则另一个小于0,不成立.

所以两个都等于0

所以2x-y+1=0,3x-2y+4=0

x=2,y=5

原式=(x-y)/(x-2y)(x²-2y)×(x-2y)²/(x+y)(x-y)-1

=(x-2y)/(x²-2y)(x+y)-1

=-8/(-42)-1

=-17/21