Answer:
D
Explanation:
2x - 6y = 8 → (1)
5x - 4y = 31 → (2)
multiplying (1) by 5 and (2) by - 2 , then adding will eliminate x
10x - 30y = 40 → (3)
- 10x + 8y = - 62 → (4)
add (3) and (4) term by term to eliminate x
(10x - 10x) + (- 30y + 8y) = 40 - 62
0 - 22y = - 22
- 22y = - 22 ( divide both sides by - 22 )
y = 1
substitute y = 1 into either of the 2 equations and solve for x
substituting into (1)
2x - 6(1) = 8
2x - 6 = 8 ( add 6 to both sides )
2x = 14 ( divide both sides by 2 )
x = 7
solution is (7, 1 )