I need help with my algebra

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?

How many credit hours will a student have to take for the two tuition costs to be equal? round the answer to the nearest tenth of an hour.

Select 2 statements that are true about the equation y+6=-10(x-3).1) the slope of the line is -102) the slope of the line is 33) one point on the line is (3,6)4) one point on the line is (3,-6)