$\"\"$

The equation is $\"\"$ .

Apply Addition property of equality: Add 5 form each side.

$\"\"$

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

$\"\"$ (Add: 13.7 + 5 = 18.7) $\"\"$

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

$\"\"$

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

The equation is true. $\"\"$

The value is $\"\"$ .