I’m confused on this type of math

Me n o w. i need t h i s. 10 points

State how many imaginary and real zeros the function has. f(x) = x3 - 20x2 + 123x - 216

Solve this problem by using a 5d process or writing and solving an equation. no matter which method you use, be sure to define your variable and write an equation to represent the relationship a rectangle has a perimeter of 30 inches. its length is one less than three times its width what are the length and wodyh of the rectangle?