the sum of two numbers is 30 and their difference is 10 . find their product .
let the numbers be x and y . then x + y = 30 and x - y = 10 x = 20 ; y = 10 xy = 20 * 10 = 200 answer : d
multiply(divide(add(30, 10), add(const_1, const_1)), subtract(divide(add(30, 10), add(const_1, const_1)), 10))