$\"\"$

The equation is $\"\"$

$\"\"$ (Substitute f = -2)

$\"\"$ (Multiply: $\"\"$ )

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

$\"\"$ (Absolute value of $\"\"$ )

$\"\"$

Compare the values, the equation is false.

$\"\"$

The given number is not a solution to the equation.