nilai (x-y) dari sistem persamaan 3/x-2/y=18 dan 5/x+4/y=8 adalah???

3/x-2/y=18
3/(x-2)=18y
3=18xy-36y dikali 4

5/x+4/y=8
5/(x+4)=8y
5=8xy+32y dikali 9

Dieliminasi
72xy+288y=45
72xy-144y=12
____________-
432y=33
y=33/432

8x+32y=5
8x+32.33/432=5
8x+1056/432=5
8x=5-1056/432
x= (5-1056/432)/8
x= 1104/3456

x-y = 1104/3456 - 33/432
=(1104-264)/3456
=840/3456