Answer:
x = 20 , y = 10
Explanation:
given the 2 equations
4x - y = 70 → (1)
5x - 2y = 80 → (2)
multiplying (1) by - 2 and adding to (2) will eliminate y
- 8x + 2y = - 140 → (3)
add (2) and (3) term by term to eliminate y
(5x - 8x) + (- 2y + 2y) = 80 - 140
- 3x + 0 = - 60
- 3x = - 60 ( divide both sides by - 3 )
x = 20
substitute x = 20 into either of the 2 original equations and solve for y
substituting into (1)
4(20) - y = 70
80 - y = 70 ( subtract 80 from both sides )
- y = - 10 ( multiply both sides by - 1 )
y = 10
solution is x = 20, y = 10