Answer:
y=7
x=6
Step-by-step explanation:
7x-7y=-7
x+y=13
rearrange the y
x+y=13
subtract x on both sides
y=-x+13
substitute
7x- 7(-x+13)=-7
7x+7x+-91=-7
simplify
14x+-91=-7
get rid of the -91, add 91 to both sides
14x=84
divide 14 from both sides
x=6
Now that we have 6 we can simplify it into the other equation
x+y=13
6+y=13
subtract 6 from both sides
y=7
x=6
Substitute it into the equation to check if both variables are correct
x+y=13
7+6=13
7(6)-7(7)=-7
simplify
42-49=-7
-7=-7
