Answer :
5y = 20x - 30
5 5
y = 4x - 6
5(4x - 6) = 20x - 30
5(4x) - 5(6) = 20x - 30
20x - 30 = 20x - 30
+30 +30
20x = 20x
20 20
x = 1
5y = 20(1) - 30
5y = 20 - 30
5y = -10
5 5
y = -2
5(-2) = 20(1) - 30
-10 = 20 - 30
-10 = -10
(x, y) = (1, -2)
5 5
y = 4x - 6
5(4x - 6) = 20x - 30
5(4x) - 5(6) = 20x - 30
20x - 30 = 20x - 30
+30 +30
20x = 20x
20 20
x = 1
5y = 20(1) - 30
5y = 20 - 30
5y = -10
5 5
y = -2
5(-2) = 20(1) - 30
-10 = 20 - 30
-10 = -10
(x, y) = (1, -2)