If you would like to know how many people attended the reunion last year, you can calculate this using the following steps:
125% of last year's attendance is 160 people
125% of x is 160
125% * x = 160
125/100 * x = 160 /*100/125
x = 160 * 100 / 125
x = 128 people (last year)
Result: 128 people attended the reunion last year.
I am assuming you want to find the simplest form of the inequality.
1.

2.

3.

1. Start
2. Subtract 9 from each side
3. Divide both sides by 3
.01 is the answer to that or one one hundredth