Whats the average between 95 and 128

What is the missing reason in step 5? linear pair postulategivendefinition of complementary anglescongruent complements theorem

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

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. how many hours after the truck's departure will the two meet?