14 15 16 I"m not sure how I decided to divide 45 by 3 to get average of 15 which lets me add one to 15 and also subtract 1 from 15

Stan's, Mark's and Wayne's ages are consecutive integers.

Stan is the youngest, and Wayne is the oldest.

The sum of all of their ages is 45.

(M - 1) + M + (M + 1) = 45

Their ages:

S = 14, M = 15, and W = 16

14,15,16

Piece of piss! WTF is your problem?

n + (n + 1) +( n + 2) = 45

3n + 3 = 45

3n = 45 - 3

3n = 42

n = 14

so

Stan's age = n = 14 .....answer//

Mark's age = n + 1 = 14 + 1 = 15......answer//

Wayne's age = n + 2 = 14 + 2 = 16 .... answer/

It might be that you do not know what the words mean. 

Consecutive integers, that means whole numbers one after another. 

So, without too much effort you can see why the ages are 14 + 15 + 16 = 45 

One way is to see that 45/3 = 15 and the 14 and 16 are either side. 

If your teacher wants you to use algebra to solve this, write it like this:- 

Let middle number be n so that either sides are n – 1 and n + 1 

Their sum is n – 1 + n +n + 1 = 3n = 45 

Middle number was 15 and those either side were 14 and 16 

let Stan be a, Mark a+1 and Wayne. a+ 2.

a + a + 1 + a + 2 = 45

3a + 3 = 45

3a = 45 - 3

3a = 42

a = 42/3

a = 14

So Stan is 14, Mark is 15 and Wayne is 16.

-

x + (x + 1) + (x + 2) = 45

3x = 42

x = 14

Stan is 14 , Mark is 15 , Wayne is 16

Let Stan is "x" years old.

Then, x+(x+1)+(x+2) = 45

3x = 42

x = 14

Ages, 14, 15, 16 respectively.