7 + 6d + 5f use d = 3 and f = 9

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?

Describe the 2 algebraic methods you can use to find the zeros of the function f(t)=-16t^2+400.

What is the solution set of the quadratic inequality x^2-5< or equal to 0