$\"\"$

The equation is $\"\"$

Apply subtraction property of equality: Subtract 3.5 form each side.

$\"\"$

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

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

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

$\"\"$

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

The equation is true. $\"\"$

The value of $\"\"$ .