Why is the sum of two rational numbers always rational? select from the options to correctly complete the proof. \ let / and / represent two rational numbers. this means a, b, c, and d are (integers, natural numbers, imaginary numbers), and b is not (zero, rational, negative) and d is not (zero, rational, negative). the product of the numbers is / where bd is not 0. because integers are closed under (addition, subtraction, multiplication, division), / is the ratio of two integers making it a rational number.

The sum of two rational numbers always rational

The proof is given below.

Step-by-step explanation:

Let a/b and c/ d represent two rational numbers.

This means a, b, c, and d are integers.

And b is not zero and d is not zero.  

The product of the numbers is ac/bd  where bd is not 0.  

Because integers are closed under  multiplication

The sum of given rational numbers a/b + c/d = (ad + bc)/bd

The sum of the numbers is (ad + bc)/bd  where bd is not 0.  

Because integers are closed under addition

(ad+bc)/bd is the ratio of two integers making it a rational number.

change of stock price/initial stock price on friday * total stock value = change of stock value

0.89/73.73 *x = 42.72

x=3539.04 = total stock value at initial stock price on friday .

total stock value at initial stock price on friday/ initial stock price on friday = number of shares

3539.04/73.73 = 48 shares

they own 48 shares of this stock