How do i find the imaginary unit?

What is the method used to multiply binomials using foil?

Find the pattern and use inductive reasoning to predict the next number in the sequence 100, 120, 60, 80, 40,

Which system of linear inequalities is represented by the graph? y > 1/3 x + 3 and 3x – y > 2 y > 1/3 x + 3 and 3x – y > 2 y > 1/3x + 3 and 3x + y > 2 y > 1/3 x + 3 and 2x – y > 2