Question

Solve the following system of equations:

−2x + y = 1
−4x + y = −1

Answer 1

Make one of the variables drop out.

I'd go for the y since it's easiest in this problem.

Time the top equation by -1.

This changes the system to:

`2x + - y = 1`

`- 4x + y = - 1`
Add the equations.


`2x + - 4x = - 2x`

`- y + y = 0`

`1 + - 1 = 0`
The equation would be:

`- 2x + 0 = 0`
Or simply:

`- 2x = 0`
Solve for x by dividing.

`x = 0 / - 2`

`x = 0`
Then, plug x into one of the original equations to find y.

I'm going to use the first one since the numbers are smaller, but you CAN use either.


`- 2(0) + y = 1`

`0 + y = 1`

`y = 1`
Put these into an ordered pair.

(0,1)

That is your answer.

Hope this helped!

:)

Answer 2

Step-by-step explanation:

Solve −2x+y=1 for y

y=2x+1

Substitute 2x+1 for y in −4x+y=−1

x=1

Substitute 1 for x in y=2x+1

y=3

Final answer:

x=1 y=3