How would i find the polynomial from the factors?

Need solving this second acceleration problem.

Find the solution on the interval [0, 2pi)

Carli has 90 apps on her phone. braylen has half the amount of apps as theiss. if carli has three timesthe amount of apps as theiss,how many apps does braylen have? let b represent the number of braylen's apps and t represent the number of theiss's apps.