Question

What is the solution to this system of linear equations? x + y = 4 x − y = 6 A: (4, 6) B: (6, 4) C: (5, −1) D: (−1, 5)

Answer 1

C

Explanation:

Given the 2 equations

x + y = 4 → (1)

x - y = 6 → (2)

Add the 2 equations term by term to eliminate y, that is

2x = 10 ( divide both sides by 2 )

x = 5

Substitute x = 5 into either of the 2 equations and evaluate for y

Substituting into (1)

5 + y = 4 ( subtract 5 from both sides )

y = - 1

solution is (5, - 1 ) → C