The sum of two numbers is 99, and their difference is 25. What are the numbers?

Question

The sum of two numbers is 99, and their difference is 25.

Answer 1

X + Y = 99  (Sum is 99)

X - Y = 25 (Difference is 25)

 

Solve for X and Y.

 

Some ways to solve the equations:

 

1. Add 2 equations to get 2X = 124. Solve for X and Y

 

2. Subtract 2 equations to get 2Y = 74.

 

3. Substitute X = Y + 25 into X + Y = 99 to get 2Y + 25 = 99.