You can put this solution on YOUR website! Let x, x+2 & x+4 be the 3 integers.
x+x+2+x+4=138
3x=138-2-4
3x=132
x=132/3
x=44 ans. for the smallest integer.
44+2=46 ans for the middle integer.
44+4=48 ans. for the largest integer.
Proof:
44+46+48=138
138=138