Start at 125 create a pattern that subtract 6 from each number

If you want a sequence that subtracts 6 each time, then we'd have to have a nth term.

125, 119, 113 etc will be your pattern

Since we are subtracting 6 each time, the nth term will start with - 6n

Then we see what that equation looks like: - 6 as the first term, - 12 as the second etc.

So we have to add a certain amount so the sequence starts at 125, which is to plus 131 to get to 125.

So now the pattern starts at 125 and decreases by 6 each term.

So U_n = - 6n + 131