I need help and step by step solutions in Calculus 3 please thank you

Consider the following. C: counterclockwise around the circle x2 + y2 = 81 from (9, 0) to (-9, 0) (a) Find a parametrization of the path C. r(t) = OSten (b) Evaluate ( x 2 + 1 2 ) ds. CUse Green's Theorem to evaluate the line integral Jc ( y - x) dx + (2x - y) dy for the given path. C: boundary of the region lying between the graphs of y = x and y = x2 - 2xEvaluate ( x - 2y + z) ds. Is S: Z =3 -X, Ox