Which is faster a car driving at a rate of 40 kph or a car at driving at a rate of 15 metres a second

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?

Factor this polynomial completely x^2-64

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.