The sum of two numbers is 100. The difference between the numbers is 6. What are the two numbers?
1 Answer
Nov 4, 2016
53 and 47
Explanation:
Let one number be x, and the other number be y.
x and y
Their sum = 100
x + y = 100
Their difference = 6
x - y = 6
We have a pair of simultaneous equations and will solve these using substitution.
x + y = 100 (1)
x - y = 6 (2)
Rearrange (2):
x - y = 6
x = 6 + y (3)
Substitute (3) into (1)
x + y = 100
(6 + y) + y =100
6 + y + y = 100
2y = 94
y =47 (4)
Substitute (4) into (3)
x = 6 + 47
x = 6 + 47 = 53
Hence the two numbers are 47, and 53.