Two Numbers with a Sum of 49 and a Difference of 9

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 =  

Sum + Difference/2

Find x by substituting given Sum and Difference into equation for x and simplify:
x =  
x =  
x =  29
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 =  
y =  
y =  20
Therefore, the two Numbers are 29 and 20
Check Sum of the two Numbers:

	2	9
	2	0
	4	9

29 + 20 = 49 ✓
Check Difference between the two Numbers:

	2	9
−	2	0
		9

29 − 20 = 9 ✓