Given: "<span>B(t)=4*e^0.8t, How many hours will it take for the population to grow to 400?" Set B(t) = 400. Then:
400=4*e^(0.8t), or
100 = e^(0.8t)
Take the natural log of both sides, obtaining
ln 100
ln 100 = 0.8t. Then t = ----------- = 5.76 hours.
0.8</span>
1.7 = <span>One and seven tenths
5.62 = </span><span>Five and sixty-two hundredths</span>
This is in slope-intercept form, so you can think of it as being y=mx+b. Invert m (the slope) and flip its sign, and then substitute the x and y values in and solve for b. The answer is y=7/2x-20.
