$\"\"$

Let n be the number.

Sum of $\"\"$ and a number is $\"\"$ .

The equation is $\"\"$ .

Apply addition property of equality: Add 6.1 to each side.

$\"\"$

$\"\"$ (Apply commutative property of addition: $\"\"$ )

$\"\"$ (Apply additive inverse property: $\"\"$ )

$\"\"$ (Apply additive identity property: $\"\"$ )

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

Check:

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

$\"\"$

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

The statement is true. $\"\"$

The value of $\"\"$ .