3 times a number less than the sum of twice the number and 1

What is the value of the expression below? (81^2)^1/8

Which statement accurately explains whether a reflection over the y-axis and a 270° counterclockwise rotation would map figure acb onto itself? a coordinate plane with figure acb with point a at 1, 1, c at 3, 4 and b at 5, 1 yes, a″c″b″ is located at a″(1, 1), c″(4, 3), and b″(1, 5) yes, a″c″b′ is located at a″(1, 1), c″(3, 4), and b″(5, 1) no, a″c″b″ is located at a″(1, 1), c″(4, 3), and b″(1, 5) no, a″c″b″ is located at a″(1, 1), c″(3, 4), and b″(5, 1)

What is the arc length when θ =pi over 3 and the radius is 5 cm? (5 points) 5 pi over 3 cm 10 pi over 3 cm 16 pi over 3 cm pi over 3 cm