Question

Solve the system of equations using elimination/combinations.

- 2x - y = - 4 x + 2y = 5

Answer 1

The solution is (1,2)

Explanation:

- 2x - y = - 4

x + 2y = 5

Multiply the second equation by 2 so we can eliminate x

2( x + 2y) = 5*2

2x +4y = 10

Add this to the first equation

- 2x - y = - 4

2x +4y = 10

----------------------

3y = 6

Divide each side by 3

3y/3 = 6/3

y = 2

- 2x - y = - 4

x + 2y = 5

Multiply the first equation by 2 to eliminate y

2(- 2x - y) = - 4*2

-4x -2y = -8

Add this to the second equation

-4x -2y = -8

x + 2y = 5

------------------

-3x = -3

Divide by -3

-3x/-3 = -3/-3

x = 1

The solution is (1,2)