There are nine books stacked on a shelf. the thickness of each book is either 1 inch or 2 inches. the height of the stack of 9 books is 14 inches. which system of equations can be used to determine x the number of 1-inch books in the stack and y, th number of 2-inch-thick books?

The median of a data set is the measure of center that is found by adding the data values and dividing the total by the number of data values that is the value that occurs with the greatest frequency that is the value midway between the maximum and minimum values in the original data set that is the middle value when the original data values are arranged in order of increasing (or decreasing) magnitude

Use sigma notation to represent the following series for 9 terms.

If tan2a=cot(a+60), find the value of a, where 2a is an acute angle