The sum of two numbers is 21. The difference of the two numbers is 19. What are the two numbers

Answer 1

Let's let x represent one of the numbers and y represent the other number. Then we can write the following equations using the information in the problem:

x + y =21

x - y = 19

Now we can use substitution to solve this system of equations.

Using the first equation, we can write: x = 21 - y

Then substitute this expression for x into the other equation:

x - y =19

21 - y - y = 19

Now combine like terms and use inverse operations to find the value of y:

21 -y - y = 19

21 - 2y = 19

21 - 2y - 21 = 19 -21

-2y = -2

-2y /-2 = -2/-2

y = 1

Then x + y = 21 : so x = 20

To check:

20 + 1 = 21

20 - 1 =19