Solve the system of equations by substitution;
From equation (1), we note that y equals 2x plus 4, hence we substitute this value of y into equation (2)
Next, we expand the parenthesis on the left side of the equation
Next we collect all like terms as follows;
Solve this and we arrive at;
Divide both sides by 9
We can now substitute for x = -1 into equation (1)
The solution is
x = -1, y= 2