How do you solve x+y=1 and 2x-y=2?

1 Answer
Oct 4, 2015

Add the two equations together to get 3x=33x=3, hence x = 1x=1, then substitute this value of xx into the first equation to find y = 0y=0.

Explanation:

If we add the two equations together, the left hand side becomes:

x+y+2x-y = 3xx+y+2xy=3x

and the right hand side becomes:

1 + 2 = 31+2=3

So 3x = 33x=3.

Divide both sides by 33 to get x = 1x=1.

Then substituting this value for xx in the first equation, we get:

1 + y = 11+y=1

Subtracting 11 from both sides we get:

y = 1 - 1 = 0y=11=0