find the average of first 7 multiples of 5 ?
"average = ( 5 + 10 + 15 + 20 + 25 + 30 + 35 ) / 7 = 20 answer is e"
divide(add(add(add(7, const_1), add(add(7, const_1), const_2)), add(subtract(5, 7), subtract(5, const_2))), 7)