There are 20 bags filled with coins that all look alike. the coins in 19 of the bags are authentic and weigh 10 ounces each. the coins in one of the bags are counterfeit and weigh 11 ounces each. with only one weighing on a scale, how can you determine which bag contains the counterfeit coins

Negative 5 1/12 + negative 4 1/4 + 6 3/4

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

What is the value of the discriminant, b2 ? 4ac, for the quadratic equation 0 = x2 ? 4x + 5, and what does it mean about the number of real solutions the equation has?