tentukan koordinat titik potong garis x+y=3 dan y=2x-1!

x+y = 3 × -2
-2x+y = -1 × 1
_____________
-2x-2y= -6
-2x+y = -1
_________+
-y = -7
y = 7
x+y = 3
x-7 = 3
x = 3+7
x = 10
(x,y) = (10,7)