Atrain runs for 3 hours at a speed of 55 km per hour and for the next 2 hours at a speed of 65 km per hour. find the average speed of the train for the 5 hours journey.

1- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis.2- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in the first question?

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

The price of a visit to the dentist is calculated according to the formula 50+100n50+100n where nn is the number of cavities the dentist finds. on your last visit to the dentist, 22 cavities were found. what was the cost of your visit?