How do you write fractions in simplest form? for example I need explanation

Question

48/66

Also I started on another one it states that I have to multiply. and I have to be sure to simplify each product

7/9 x 3/5
My answer: 21/45 I just don't know what goes after this step?

to simplify 48/66 you have to find a common factor that can be divided from both the numbers top and bottom. for instance, the number 6 is a common factor.

what times 6 equal 48? 8
What times 6 equals 66? 11

so the answer is 8/11.

same with other one. after you multiply, you simplify. a common factor is 3

What times 3 equals 21? 7
what times 3 equals 45? 15

so the answer is 7/15.

if you pick a small common factor and you still see that it can be simplified more, that pick another number and do it again until you can't simplify it anymore

Thank you so much you've explanations make more sence then the book. I wrote all the steps yousaid so i can keep them in my notes so when i get stuck on similar problems.