if the sum and difference of two numbers are 15 and 10 respectively , then the difference of their square is :
"let the numbers be x and y . then , x + y = 15 and x - y = 10 x 2 - y 2 = ( x + y ) ( x - y ) = 15 * 10 = 150 . answer : b"
subtract(power(divide(add(15, 10), const_2), const_2), power(subtract(15, divide(add(15, 10), const_2)), const_2))