Find the solution of this system of equations. separate the x- and y-values with a comma. x - 4y = 12 and x - y = 0

Use elimination and subtitution method to solve the problem.
First, eliminate x and you'll find the value of y
x - 4y = 12
x -  y  = 0
- (substract)
     -3y = 12
        y = 12/-3
        y = -4

Second, subtitute -4 as y and you'll find the value of x
x - y = 0
x- (-4) = 0
x + 4 = 0
x = -4

The solution
x,y = -4,-4

D) the x-intercept represents adam's commission pay when he had zero total sales