Do these both plsss ill give like 50 points

Find the value of the cosine for angle a

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?

If the discriminant if a quadratic equation is 4 which statement describes the roots?