5.
The sum of three consecutive integers is 228. You can write this situation, in an algebraic way, as follow:
x + (x + 1) + (x + 2) = 228
where the lower number is x, and the largest number is (x + 2).
You solve the previous equation for x:
x + (x + 1) + (x + 2) = 228 eliminate prenthesis
x + x + 1 + x + 2 = 228 sum similar terms
3x + 3 = 228 rest 3 both sides
3x = 228 - 3
3x = 225 divide by 3
x = 225/3
x = 75
Then, the lower number is 75, and the largest one is (75+2) = 77