Question

the sum of two numbers is 18 the difference of the numbers is 4 find the numbers

Answer 1

let the two numbers be x&y

x+y=18

x-y=4

add the equation we get

2x=22

x=11

y=7

Answer 2

(18+4)/2 = 22/2 = 11

(18-4)/2 = 14/2 = 7