What is the sum or difference?
3x^3+5x^3
and
8y^7-6y^7

Show your work please

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?

Donald has x twenty-dollar bills and 11 ten-dollar bill. how much money does donald have? write your answer as an expression.

3c2 + 2d)(–5c2 + d) select all of the partial products for the multiplication problem above.