Ms. Buback is competing in a race in which she both runs and rides a bike. She runs 5 kilometers in 0.5 hours and rides her bike 20 kilometers in 0.8 hours. At the rate given, how many kilometers can she bike in one hour?

25.02 km/h

Step-by-step explanation:

60 min × 0.8 = 48 min

20 km÷48 = 0.417 km/min

0.417 × 60 = 25.02 km

Step-by-step explanation:

To find the zeros, set y=-4(x - 3)2 + 8 = 0.  Then -4(x - 3)^2 = -8, and:

4(x - 3)^2 = 8.  Dividing both sides by 4 yields (x - 3)^2 = 2.

Taking the square root of both sides yields x - 3 = ±2, so that

x = 3 ±2, or x = 5 and x = 1.  These are the zeros. The correct interpretatioon is A:  where the daily profit is $0.