Afalling object travels a distance given by the formula
d = 5t + 16t2,
where t is measured in seconds and d is measured in feet. how long will it take for the object to travel 21 ft?

Evaluate the expression for the given value of the variable 7a - 4a for a =8

How many real-number solutions does the equation have? -4x^2 + 10x + 6 = 0 a. no solutions b. two solutions c. infinitely many solutions d. one solution

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?