Given a quadratic equation

you can find its solutions with the following formula:

You equation is identified by the coefficients

Which means the solutions are

So, the answers are B and D
that would be 20 miles per hour. If in 8 hours you're going 160, then divide 160 by 8 and you'd get 20. Each hour is 20 miles. or 8 times 20 is 160. Your answer is 20 miles per hour