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

The equation is $\"\"$

According to subtraction property of equality: If a = b then a – c = b – c.

$\"\"$ (Subtract 6 from each side)

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

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

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

The value of a =11.