The diameter of two internally tangent circles are 28 and 22 cm. Find the distance between the centres of the
circles.

If you have the following equation, 2/3x+5/6-x=2-3/4x what would you multiply each term by to get rid of all the fractions

What is the perimeter of an equilateral triangle if each side is (x+3)?

The patient recovery time from a particular surgical procedure is normally distributed with a mean of 5.2 days and a standard deviation of 1.7 days. what is the probability of spending more than 2 days in recovery? (round your answer to four decimal places.)