bantuin aku please bgt..pakai cara yaa

2. metode eliminasi subtitusi
x. - y = 5
2x + y = 4
----------------- +
3x = 9
x = 9/3
x=3

x - y = 5
3 - y = 5
-y=5-3
-y = 2
y = -2
{(3,-2)}