The rate of growth (the slope of the transformed curve) is first higher than for an exponential function, but later it goes down. ... Initially, the quadratic function grows much faster. The function x² grows from 0 to 1 in finite time, while the exponential function takes from minus infinity to 0.
6.5 because you instantly take $9.50 away from $55. After you get that answer, you will have 45.5. Then divide 45.5 by 7 which will give you 6 and a half hours.
