X = 3y - 6....so sub 3y - 6 in for x in the other equation
2(3y - 6) - 4y = 8
6y - 12 - 4y = 8
2y = 8 + 12
2y = 20
y = 20/2
y = 10
x = 3y - 6
x = 3(10) - 6
x = 30 - 6
x = 24
solution is (24,10)
The point (a,b) is (5,7) . Therefore, the equation of the line is y=7