Question

(04.01)Solve the following system of equations by substitution and select the correct answer below:4x − 6y = 28 8x − 4y = 24

Answer 1

It is convenient to divide the second equation by 2, then substitute for 4x in the first equation.
4x -2y = 12
4x = 12 + 2y . . . . solve for 4x

(12 +2y) -6y = 28 . . . . substitute for 4x
-4y = 16 . . . . . . . . . . . . subtract 12
y = -4 . . . . . . . . . . . . . .divide by -4

4x = 12 + 2(-4) = 4
x = 1

The solution is (x, y) = (1, -4).