The formula p=2l+2w solve for w not l

Noor brought 21 sheets of stickers. she gave 1/3 of a sheet to each of the 45 students at recess. she wants to give teachers 1 1/2 sheets each.

Sandy is ordering bread rolls for her party,she wants 3/5 of the rolls to be whole wheat. what other factions can represent part of the rolls that will be whole wheat? shade the models to show your work.

What is the the greatest common factor ?