How do i find the imaginary unit?

Which value is not a solution of 8x^3 – 1 = 0

High schoolmathematics 5 points keith is the leading goal scorer for a team in an ice hockey league. last season, he scored 42 goals in 82 games. assuming he scores goals at a constant rate, what is the slope of the line that represents this relationship if the number of games is along the x-axis and the number of goals is along the y-axis?

State one method by which you can recognize a perfect square trinomial.