$\"\"$ $\"\"$

The equations are x + y = 0 and 3x + y = – 8 .

$\"\"$ Equation(1)

$\"\"$ Equation (2)

Since x = – y, substitute – y for x in the second equation.

$\"\"$

$\"\"$ (Product of two different signs is negative)

$\"\"$ (Add: $\"\"$ ) $\"\"$

According to division property of equality: Divide each side by 2.

$\"\"$

$\"\"$ (Cancel common terms)

$\"\"$ (Multiply each side by negative one)

$\"\"$ (Product of two same signs is positive) \ \

$\"\"$

Now, find the x value by substituting $\"\"$ in Equation 1

$\"\"$

The solution is $\"\"$ .