How do i find out if -5/3 is a zero of the equation 0=18c^3-50c?

Given tan∅=4/3 and π< ∅< (3π)/2; find cos2∅ a. -24/25 b. 24/25 c. -24/7 d. -7/25

Each morning papa notes the birds feeding on his bird feeder. so far this month he has see. 59 blue jays, 68 black crows, 12 red robin's and 1 cardinal. what is the probability of a blue jay being the next bird papa sees

Write the expression 7x^3-28xy^2 as the product of 3 factors