The difference of 25 and a number added to triple another number The phrase a number means an arbitrary variable, let's call it x: x The difference of 25 and a number means we subtract x from 25: 25 - x The phrase another number means a different arbitrary variable, let's call it y: y Triple another number means we multiply y by 3: 3y The phrase added to means we add 25 - x to 3y 25 - x + 3y
