if p and q are prime numbers , how many divisors does the product p ^ 4 * q ^ 9 have ?
"when a number n = a ^ x * b ^ y , where a and b are prime numbers , and x , y are positive integers , the number of divisors of n = ( x + 1 ) ( y + 1 ) therefore , the answer is d . 5 * 10 = 50"
multiply(add(4, const_1), add(9, const_1))