1. The sum of two numbers is 5. The difference of the numbers is 11. What are the two numbers? x = 1st number y = 2nd number x + y = 5 x – y = 11 2x = 16 2 2 x = 8 8 and -3 x + y = 5 8 + y = 5 -8 -8 y = -3

2. Two numbers have a sum of 25. One number is five more than the other. Find the numbers. x + y = 25 (y + 5) + y = 25 2y + 5 = 25 -5 -5 2y = 20 2 2 y = 10 x + y = 25 x = y + 5 10 and 15 x = y + 5 x = 10 + 5 x = 15

3. One number is two more than three times another. Their sum is 26. Find the numbers. x + y = 26 (3y + 2) + y = 26 4y + 2 = 26 -2 -2 4y = 24 4 4 y = 6 x = 3y + 2 x + y = 26 6 and 20 x = 3y + 2 x = 3(6) + 2 x = 18 + 2 x = 20