The area of a cross section of earth at the equator is 12796,483 sq kilometers use the formula A=3.14r to the second power to find the radius

Find three consecutive numbers such that the sum of one-fourth the first and one-fifth the second is five less than one-seventh the third

Lance lived in portugal and brazil for a total of 14 months to learn portuguese. he learned an average of 130 new words per month when he lived in portugal, and an average of 150 new words per month when he lived in brazil. in total he learned 1920 new words. write a system of equations to represent the situation. use x to represent portugal, and y to represent brazil

The sum of the speeds of two trains is 720.2 mph. if the speed of the first train is 7.8 mph faster than the second train, find the speeds of each.