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

The equation is $\"\"$

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

According to addition property of equality: If a = b then a + c = b + c.

$\"\"$ (Add 18 to each side)

$\"\"$ (Additive inverse property: $\"\"$ )

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

Check:

To check the solution, substitute $\"\"$ in original equation.

$\"\"$

$\"\"$ (Subtract: $\"\"$ )

Compare the values, the equation is true.

$\"\"$

The value of $\"\"$