100 POINTS PLEASE HELP IM BEGGING U I NEED TO PASS (summer school)

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

3x = 729 solve for x plz . it's urgent. will mark

Franklin is purchasing a home for $82,107 and is financing 80% of it. the documentary stamp tax on the deed in his state is $0.70 per $100 or portion thereof. how much will he pay for the documentary stamp tax?