Convert 5/8 to a decimal and tell whether it terminates or repeats

Find the roots of the polynomial function f(x) = x^3 + 2x^2 + x

Acompany manufactures three types of cabinets. it makes 110 cabinets each week. in the first week, the sum of the number of type-1 cabinets and twice the number of type-2 cabinets produced was 10 more than the number of type-3 cabinets produced. the next week, the number of type-1 cabinets produced was three times more than in the first week, no type-2 cabinets were produced, and the number of type-3 cabinets produced was the same as in the previous week.

Tan198=asin164=? how to solve this? ?