$\"\"$

The equation is $\"\"$ .

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

$\"\"$ (Add 3 to both sides)

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

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

$\"\"$ \ \

According to multiplication property of equality:

For any number a, b and c, If a = b then ac = bc.

$\"\"$ (Multiply each side by 7)

$\"\"$ (Cancel common terms)

a = 7 (Multiply: $\"\"$ )

$\"\"$

Check:

To check the solution, substitute a = 7 in original equation.

$\"\"$

$\"\"$ (Cancel common terms)

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

Compare the values, the equation is true.

$\"\"$

The value of a = 7.