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

The sentence is “A number increased by 8 is 23”

Let n be the number.

The word increased indicates addition, and the symbol is $\"\"$

Thus, the numerical expression is “ $\"\"$ ”

The equation is, $\"\"$ $\"\"$

Subtraction property of equality: Subtract 8 from each side.

$\"\"$

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

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

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

The value of the expression is 15.