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

\

The equation is $\"\"$ .

\

According to addition property of equality: Add 3 to each side.

\

$\"\"$

\

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

\

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

\

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

\

According to multiplication property of equality:Multiply each side by 7.

\

$\"\"$

\

$\"\"$ (Cancel common terms)

\

$\"\"$ (Multiply: $\"\"$ ) $\"\"$

\

Check:

\

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

\

$\"\"$

\

$\"\"$ (Cancel common terms)

\

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

\

Compare the values, the equation is true. $\"\"$

\

The value of $\"\"$ .