if the average ( arithmetic mean ) of ( 2 a + 16 ) and ( 3 a - 8 ) is 79 , what is the value of a ?
"( ( 2 a + 16 ) + ( 3 a - 8 ) ) / 2 = ( 5 a + 8 ) / 2 = 79 a = 30 the answer is b ."
divide(subtract(multiply(79, 2), subtract(16, 8)), add(2, 3))