What is 86.5/100 in lowest terms?

Lowest term 9/11 - 5/12. Please need help confuse

580/145 lowest term

17/21 - 2/21 lowest term

10/15 lowest term

(3/7)(-2/5) lowest term

(7/8)(- 7/3) Lowest term

12/7 in lowest term

What does "lowest term" mean in the context of the expression cos^2 θ - 1/4 cos θ - 1?

24/90 to its lowest term

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