\fIf s denotes the length of the arc of a circle of radius r subtended by a central angle 0, find the missing quantity. r=. feet, s = 12 feet, 0 = ? 36 radians 20 radians 20 36 0Use the properties of logarithms to find the exact value of the expression. Do not use a calculator. \fExpress as a single logarithm. In x2 - 3x - 54 - In x- 1 x + 8 x2+5x - 6 + In (x2 - 18x + 81), x > O O In 3(x - 9) 2(x - 1)(x + 8) In (x - 9)3 (x + 8) (x - 1)2 O In (x - 9)3 (x - 1)2 (x + 8) In 3(x - 9)(x + 8) 2(x - 1)