Add two brackets in this equation

In the football stadium, there are 18 empty seats out of 360 total seats. (1a) write the ratio of empty seats to total seats as a fraction in simplest form. (1b) then explain its meaning.

Evaluate the following expression 1/3^2

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.