How do you solve this system of equations: a+ b = 4 and a - b = 10?

1 Answer
Oct 24, 2017

a=7 and b=-3

Explanation:

If a+b=4 and we subtract b from both sides, we get a=4-b

a-b=10
Since we know that a=4-b, we can substitute a with that.
4-b-b=10->
4-2b=10

Subtract 4 from both sides:
-2b=10-4->
-2b=6

Divide both sides by -2

(-2b)/(-2)=6/(-2)->
b=-3

Since we know a=4-b and b=-3, a=4-(-3) which is equal to a=7.