If a_1=4a 1 =4 and a_n=-3a_{n-1}a n =−3a n−1 then find the value of a_4a 4

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.

Your food costs are $5,500. your total food sales are $11,000. what percent of your food sales do the food costs represent?

Each person in an it department of 25 people works on at least one of 3 major projects: system security, program implementation, platform development. 10 people work on system security, 13 work on program implementation, and 12 work on platform development. 4 people work on system security and platform development, 5 people work on program implementation and platform development, and 2 people work on all three projects. how many people work on system security and program implementation?