When dividing fractions, Why do we invert (find the reciprocal) and multiply?

The science fair judges will be teachers and volunteers. Each judge will view 5 projects. There are 133 science teachers. What is the fewest number of volunteers needed to have enough judges

A bottle holds 690 milliliters of liquid. How much is this in ounces? Use the following conversion: 1 ounce is 30 milliliters.

2 y = x2 + 4x how do u solve for x2

What is the greatest common factor for 21 and 40?

Troy is 1.4 meters tall. Edna is 54 centimeters shorter. How tall is Ena

What is 92% of 85 (show the math used to arrive at solution

Mary is the presenter of a weekly radio show. She plays five new songs for every two old songs. Last week she played 15 new songs. How many songs did she play altogether?

What is 7/100 in decimal

Q: It takes Zach 15 minutes to walk 7 1/2 blocks to the swimming pool. At this rate how many blocks can he walk in one minute?

I varies inversely with x and x=3.25 when y=4.5 what is the value of the x when y=3.75 A) 5.2 B) 3.9 C) 2.7 D) 3.2