Which expressions are equivalent to x 2 y x 2 x+2y+x+2x, plus, 2, y, plus, x, plus, 2 ?

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?

The radius of the earth is two times the radius of the moon. what fraction of the volume of the earth is the volume of the moon?

If a 36 inch yardstick casts a 21 foot shadow, how tall is a building whose shadow is 168 feet? what is the scale factor