Question

The linear combination method is applied to a system of equations as shown.

4(.25x + .5y = 3.75) → x + 2y = 15
(4x – 8y = 12) → x – 2y = 3
2x = 18
What is the solution of the system of equations?

(1,2)
(3,9)
(5,5)
(9,3)

Answer 1

(9,3)

Explanation:

4(.25x + .5y = 3.75) → x + 2y = 15

(4x – 8y = 12) → x – 2y = 3

2x = 18

Divide both sides by 2

x = 9

Substitute x = 9 into x + 2y = 15

9 + 2y = 15

Subtract 9 from both sides

2y = 6

Divide both sides by 2

y = 3

Solution

(9, 3)