Precalc please help

7. Convert the following in Cartesian Form: a) x = 3t + 1 and y = -6t b) x = t2 - 1 and y = Vt - 4 c) x = 2 sint and y = 2 cost 8. Convert the Cartesian curve (x - 2) + (y - 1)? = 4 into Polar form. 9. Make a sketch of x = 2 cost, y = 3 sint for the domain 0 = t = 2n