Define variables:
Let x = larger number and y = smaller number
Resulting system of equations:
x + y = Sum
x − y = Difference
Solve the system of equations for x (larger number):
x =
Find x by substituting given Sum and Difference into equation for x and simplify:
x =
x =
x = 18
Solve the system of equations for y (smaller number):
y =
Find y by substituting given Sum and Difference into equation for y and simplify:
y =
y =
y = 3
Therefore, the two Numbers are 18 and 3
Check Sum of the two Numbers:
18 + 3 = 21 ✓
Check Difference between the two Numbers:
18 − 3 = 15 ✓
Let x = larger number and y = smaller number
Resulting system of equations:
x + y = Sum
x − y = Difference
Solve the system of equations for x (larger number):
x =
Sum + Difference/2
Find x by substituting given Sum and Difference into equation for x and simplify:
x =
21 + 15/2
x =
36/2
x = 18
Solve the system of equations for y (smaller number):
y =
Sum − Difference/2
Find y by substituting given Sum and Difference into equation for y and simplify:
y =
21 − 15/2
y =
6/2
y = 3
Therefore, the two Numbers are 18 and 3
Check Sum of the two Numbers:
| 1 | ||
| 1 | 8 | |
| 3 | ||
| 2 | 1 |
Check Difference between the two Numbers:
| 1 | 8 | |
| − | 3 | |
| 1 | 5 |
