Question

The sum of two numbers is 20 and their difference is 6. Find the numbers.

Answer 1

Let the number be a & b

a + b = 20

a - b = 6

adding we get

(a + b) + (a - b) = 20 + 6

a + b + a - b = 26 [x + (y + z) = x + y + z]

2a = 26

a = 13

Subtracting we get

(a + b) - (a - b) = 20 - 6

a + b - a + b = 14 [x - (y - z) = x - y + z]

2b = 14

b = 7

Hence, the numbers are 7 & 13