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>
Bill and Joe have 60 dollars between them. Bill has half as much as Joe.
so Bill = B and Joe = J
20 (B) + 40 (J) = 60
Bill has half the amount of Joe, and so 40/2 = 20
subtract 60 from 20 (the answer for Bill) and you get 40, (the answer for Joe)
hope this helps
8 - (-d) = 43
8 + d = 43 <==
1. 12in (1ft)+X=28in
2. 6in.+X=42
3. 170.5sq.ft./15.5=x
4. 120ft/12ft=x10sec.