Answer:
a+2
Step-by-step explanation:
Set all three numbers so they are "a". This way the mean of these three numbers is "a". We are given that the first and second number stay the same so we have 1st#="a" and 2nd#="a". The third number is increased by six so it'll be "a"+6 so we have 3rd#="a"+6. Then we solve for the mean.
[(a) + (a) + (a+6)]/3. Simpliyfying it we get the mean is "a"+2
