Tolong no 13 dengan caranya :)

2/5+1/6=3
---------------×30
12 5 90

1/10-2/3=-7/2
-------------------×30
3 -20 -105

12 5 90
3 -20 -105
| |
| x=-1800-(-525)/-240-15=-1275/-255=5
y=270-(-1260)/15-(-240)=1530/255=6

2x-y=2(5)-6
=10-6
=4(C)
Semoga membantu^.^