Two buses leave New York at the same time traveling in opposite directions. One travels at in average speed of 77 MPH and the other at 68mph. In how many hours will they be 435 miles apart? Let x = time of travel for the first bus and y = time for the second bus. The system that models the problem is × = y
77x+68y=435 solve the system by using the method of additon.

Prove that the value of the expression 7^8–7^7+7^6 is divisible by 43.

On traditional maps, earth is represented in a flat plane, or by euclidean geometry. however, a globe is a more accurate model that comes from elliptical geometry.how does a globe represent the fact that there are no parallel lines in elliptical geometry? the equator is not parallel to any other latitudinal lines. the north and south poles are never connected by a geodesic. the geodesics connecting the north and south poles never intersect. the geodesics connecting the north and south poles intersect at both of the poles.

On the first of each month sasha runs a 5k race she keeps track of her times to track her progress her time in minutes is recorded in the table