Perform the operation(s) and write the answer in simplest form. 7 5/9-3 7/9

Find the measure of the interior angles of the following regular polygons: a triangle, a quadrilateral, a pentagon, an octagon, a decagon, a 30-gon, a 50-gon, and a 100-gon.

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

In a sale there is 25% of all prices a chair costs £45 in sale how much was it before the sale