So 8 > 5+ radical number 7 > 7, so the fractional part of 5+ radical number 7 is 5+ radical number 7-7= radical number 7-2.

Similarly, 3 > 5- radical number 7 > 2, so the fractional part of 5- radical number 7 is 5- radical number 7-2=3- radical number 7.

So X+Y= radical number 7-2+3- radical number 7= 1.

The one upstairs won't. Don't mislead others.