Question 840110
let number 1 = a
let number 2 = b
a + b = 80------(i)
assume a = largest number
a - 4b = 5------(ii)
using substitution
from eqn i   b = 80 - a
a - 4(80 - a) = 5-------(ii)
a + 4a = 325
a = 65
hence b = 15
the smaller number is 15