$\"\"$

The equation is $\"\"$ .

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

$\"\"$ (Subtract 7.1 from each side)

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

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

Check:

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

$\"\"$

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

The equality is true. $\"\"$

The value of $\"\"$ .