In order to know when the Nile would flood each year, what did the Egyptians invent? Group of answer choices

A calendar

Pyramids

Papyrus

Writing

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 sec theta = 5/3 and the terminal point determined by theta is in quadrant 4, then

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 + 4x + 5 = 0