If (5x-60) &# 178; and the radical Y-3 are opposite to each other, then the value of the radical X-Y is ()

If (5x-60) &# 178; and the radical Y-3 are opposite to each other, then the value of the radical X-Y is ()

(5x-60) & # 178; is opposite to the radical Y-3
∴(5x-60)²+√(y-3)=0
∴﹛5x-60=0
y-3=0
x=12,y=3
√﹙x-y)=√9=3