Help it's due tomorrow

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?

Which set of side lengths form a right side? a) 3ft,6ft,5ft b)50 in,48in,14in c)53m,48m,24m d)8cm,17cm,14cm

Which of the following expressions cannot be simplified to x – 2?