The sum of three consecutive integers is 42

[math_celebrity]

Let the 3 integers be x, y, and z.
y = x + 1
z = y + 1, or x + 2.

Set up our equation:
x + (x + 1) + (x + 2) = 42

Group our variables and constants:
(x + x + x) + (1 + 2) = 42
3x + 3 = 42

Subtract 3 from each side:
3x = 39

Divide each side of the equation by 3:
x = 13
So y = x + 1 = 14
z = x + 2 = 15

(x,y,z) = (13,14,15)