Which number has the greatest value?
A.50/20
B.23/8
C.22/7
D.2 1/2

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

Name the quadrilaterals that have four equal sides.

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.