3x + 4y = 38 ( equation 1) ----> ×5
5x - 5y = -30 ( equation 2) ----> ×3
When you multiply eqn 1 by 5 you get, 15x + 20y = 190
And when you multiply eqn 2 by 3, you get, 15x - 15y = -90
Then you solve both equations by subtracting eqn 2 from eqn 1
15x + 20y = 190
15x - 15y = 90
Then 15x - 15x gets cancelled and 20y - (-15y) gives 35y and 190 - (-90) gives 280.
So that gives 35y = 280
y = 8
And when you replace y = 8 in any of the two equations, x = 2
