The revenue from selling x shirts is r(x) = 15x. the cost of buying x shirts is c(x) = 7x + 20. the profit from selling x shirts is p(x) = r(x) – c(x). what is p(x)? a. p(x) = 22x – 20 b. p(x) = 22x + 20 c. p(x) = 8x – 20 d. p(x) = 8x + 20

The base of a triangle exceeds the height by 9 inches. if the area is 180 square inches, find the length of the base and the height of the triangle.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

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?