Solve the following system:
{3 x-y = -7
x-3 y = -13
In the second equation, look to solve for x:
{3 x-y = -7
x-3 y = -13
Add 3 y to both sides:
{3 x-y = -7
x = 3 y-13
Substitute x = 3 y-13 into the first equation:
{3 (3 y-13)-y = -7
x = 3 y-13
3 (3 y-13)-y = (9 y-39)-y = 8 y-39:
{8 y-39 = -7
x = 3 y-13
In the first equation, look to solve for y:
{8 y-39 = -7
x = 3 y-13
Add 39 to both sides:
{8 y = 32
x = 3 y-13
Divide both sides by 8:
{y = 4
x = 3 y-13
Substitute y = 4 into the second equation:
{y = 4
x = -1
Collect results in alphabetical order:
Answer: x = -1 and y = 4
