What is the quadratic equation in which the roots are 2+i and 2 - i

In a school 2/3 of the students study a language of those who study a language 2/5 study french

In a small section of a stadium there are 40 spectators watching a game between the cook islands and fiji. they all support at least one of the two teams. 25 spectators support the cook islands and 16 of these support both teams. how many support only fiji?

Geometry - finding area of regular polygons and sectors (check my math, i can’t find the error)