Two trains leave the same station at the same time, but are headed in opposite directions. one train travels at 70 mph and the other train travels at 80 mph. how much time passes until the trains are 600 mi apart?

Which of the following system of equation is not equal to the system of equations is not equal to the system of equations shown below

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

Prove sin2a + cos2a - 1 / sin2a + cos2a + 1 = 1 - tana / 1 + cota