$\"\"$

The equation is $\"\"$ .

According to subtraction property of equality: If a = b then $\"\"$ .

$\"\"$ (Subtract 7 from each side)

(Apply commutative property of addition: a + b = b + a)

$\"\"$

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

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

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

$\"\"$ (Multiply each side by negative one) \ \

$\"\"$ (Product of two same signs is positive) $\"\"$

The value of $\"\"$ .