How does the discriminant determine the number of real solutions a quadratic equation have?

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.

Find the number of liters in 12.8 gal of gasoline. round to the nearest hundredths

Mis the midpoint of rq if rm equals 2x + 5 and mq equals 4x - 9 what is the length of rq