Answer:
x\y=5\3. ..........[I]
X=5y\3
X+y=56
X=56-y.........[ii]
substitute [I] &[ii]
5y\3=56-y
5y=3[56-y]
5y=168-3y
5y-3y=168
2y=168
y=168\2
y=84........[iii]
substitute [iii] in [ii]
X=56-84
X=-28
x-y=-28-84
=-112
