What is the conjugate of the binomial squareroot 6+4

Could somebody me with this radical simplification?

Melanie is buying a bathing suit that costs 39.99. she is given a discount at the cash register of $6.00 when she scratched 15% off on a game piece for a store promotion. what will the sale price of melanie’s bathing suit be?

Write the equation of the circle centered at (10,-2) with radius 2.