How do you solve the system of equations: 4x + 2y = 14 and 4x + 3y = 6?

1 Answer
Nov 6, 2016

x = 15/2 and y = -8

Explanation:

Step 1) First solve the second equation for y while keeping both sides of the equation balanced:

4x + 2y = 14

4x + 2y - 4x = 14 - 4x

2y = 14 - 4x

(2y)/2 = (14 - 4x)/2

y = 7 - 2x

Step 2) Substitute 7 - 2x for y in the first equation and solve for x while keeping both sides of the equation balanced:

4x + 3(7 - 2x) = 6#

4x + 21 - 2x = 6

2x + 21 = 6

2x + 21 - 21 = 6 - 21

2x = -15

(2x)/2 = 15/2

x = 15/2

Step 3) Substitute 15/2 for x in the solution for Step 1 to find y:

y = 7 - 2(15/2)

y = 7 - 15

y = -8