Out of a total of 10 college textbooks estimate the standard deviation of their ages if the oldest textbook is known to be 7.9 years old and the newest textbook is 1.3 years old. A. 0.5 years
B. 1.1 years
C. 2.3 years
D. 2.9 years
E. 3.3 years

Simply 8x squared + 5(7x squared- x) - 2x =

Atriangle has an area of 72 square inches. if the base of the triangle has a length of 18 inches, what is the height of the triangle? use the formula for the area of a triangle: area = (base)(height) type a numerical answer in the space provided. do not include the units or spaces in your answer.

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.