Please help me! It’s due soon!

When is g(x) = 0 for the function g(x) = 5.23x + 4?

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?

What is the equation of a line that passes through points (0, 4) and (-4,-8)?