Question

The sum of two numbers is 45 and their difference is 5. Find the smaller and the bigger number

Answer 1

smaller number is 20 and larger number is25

Explanation:

let x and y represent the 2 numbers, with x > y

form 2 equations in x/ y and solve simultaneously

x + y = 45 → (1)

x - y = 5 → (2)

adding the 2 equations term by term will eliminate y

(x + x) +(y - y) = 45 + 5

2x + 0 = 50

2x = 50 ( divide both sides by 2 )

x = 25

substitute x = 25 into (1) and solve for y

25 + y = 45 ( subtract 25 from both sides )

y = 20

smaller number is 20 and larger number is 25