What is the percentage of change from 400 to 300?

Which of the following would represent the sum of 3 consecutive integers if x is the first integer?

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?

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1