Y-x=0 X+2y=9 Subsitusikan metode grafik SPLDV

y - x = 0 => y = 0 + x
x + 2y = 9
**
x + 2y = 9
x + 2(0 + x) = 9
x + 0 + 2x = 9
3x = 9
x = 3
masukkan x = 3 kesalah satu persamaan
y - x = 0
y - 3 = 0
y = 0 + 3
y =3