Question

Three consecutive integers can be represented by the variable n, n+1 and n+2. If the sum of three consecutive integers is 57, what are the integers? I am confused with what it is asking.

Answer 1

You have some unknown integer $n$, and you know that adding this and the next two integers, $n+1$ and $n+2$, gives a total of 57.

This means

$n+(n+1)+(n+2)=57$

The task is to find all three unknown integers. Notice that if you know the value of $n$, then you pretty much know the value of the other three integers.

To find $n$, solve the equation above:

$n+(n+1)+(n+2)=3n+3=57\implies 3n=54\implies n=\dfrac{54}3=18$

So if 18 is the first integer, then others must be 19 and 20.

Answer 2

You have to make the equation n+(n+1)+(n+2)=57.
So, 
n+(n+1)+(n+2)=57
3n+3=57
     -3  -3
3n=54
Divide 3 on both sides
n= 18

Answer:
n= 18
n+1= 19
n+2=20