Hey there! I'm happy to help!
Let's call our number n. Here is the information we have.
n+5=5n
We subtract 5n from both sides.
n+5-5n=0
Combine like terms.
-4n+5=0
Subtract 5 from both sides.
-4n=-5
Divide both sides by -4.
n=5/4
Our number is 5/4 or 1 1/4. If you add 5 to 5/4, you get 6 1/4. If you multiply 5/4 by 5, you get 25/4 which is also 6 1/4.
Have a wonderful day! :D