Change the sign on the first one, making it -2x -y = 1
Then combine the terms you have,
-2x-y=1
and
6x+y=-21
And this will give you
4x=20
Then solve that equation for x by dividing both sides by 4, giving you x=4
Then plug 5 into x’s place in either of the original equations.
This is if you use the first equation
2(5)+y=-1
Solve for y by simplifying
10+y=-1
Then subtract 10 from both sides
y=-11.
The final answer is x=5 and y=-11
