Question

Solve the system with elimination.
2x - y = 7
5x - 2y = 4

Answer 1

(- 10, - 27 )

Explanation:

given the system of equations

2x - y = 7 → (1)

5x - 2y = 4 → (2)

multiplying (1) by - 2 and adding the result to (2) will eliminate y

- 4x + 2y = - 14 → (3)

add (2) and (3) term by term to eliminate y

(5x - 4x) + (- 2y + 2y) = 4 - 14 , that is

x + 0 = - 10

x = - 10

substitute x = - 10 into either of the 2 original equations and solve for y

substituting into (1)

2(- 10) - y = 7

- 20 - y = 7 ( add 20 to both sides )

- y = 27 ( multiply both sides by - 1 )

y = - 27

solution is (- 10, - 27 )