What is the value of the digit 7 in the population of Memphis? How much greater is the value of the place that the 7 is in than the value of the place to the right?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

What is the absolute value of -100000000000000?