$\"\"$

The expression is $\"\"$ .

$\"\"$ (Distributive Property: a (b + c) = ab + ac)

$\"\"$ (Multiply: 3 $\"\"$ 4m = 12m)

$\"\"$ (Multiply: 2m $\"\"$ 4 = 8m)

$\"\"$ (Commutative Property: a + b = b + a) \ \

$\"\"$

$\"\"$ (Associative Property: (a + b) +c = a + (b + c))

$\"\"$ (Distributive property: a (b + c) = ab + ac)

$\"\"$ (Add: 12 + 2 =20)

$\"\"$

The simplified expression is $\"\"$ .