$\"\"$ $\"\"$ $\"\"$

\

The expression is $\"\"$ .

\

According to addition property of equality: if a = b, then a + c = b + c.

\

$\"\"$ (Add 8t to each side)

\

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

\

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

\

According to subtraction property of equality: if $\"\"$ , then $\"\"$ .

\

$\"\"$ (Subtract 90 from each side)

\

$\"\"$ (Commutative property: a + b = b + a)

\

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

\

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

\

According to division property of equality: if $\"\"$ , then $\"\"$ .

\

$\"\"$ (Divide each side by 10)

\

$\"\"$ (Cancel common terms)

\

$\"\"$ (Divide: $\"\"$ ) $\"\"$

\

The value of $\"\"$ .