Suppose you are building a rectangular pen for your goats. you use 400 feet of fencing for the pen. let represent the pen’s length (in feet).
part a: which of the following expressions could represent the width of the pen?
a 2+400 b 200− c 2−400 d 400(2)
part b: find the width of the pen if you make the pen 80 feet long.
part c: find the width and the area of the pen if the length is 90 feet.

linearly: 8560 bacteria

exponentially: approximately 75233 bacteria

step-by-step explanation:

assuming it is not exponential (we would have some really complicated logarithms), let's say it is linear. then, after 5 hours, it increased by 1200 bacteria, so every hour it increases by 240 bacteria. this means that after 19 hours, we get 19 * 240 + 4000 bacteria or 3800 + 760 + 4000 = 7800 + 760 = 8560 bacteria.

because it says round your answer, i will do this exponentially (with a calculator, of course). first, we need to find how much it multiplies by every hour, by taking the 5th root of 52/40 or 13/10. this is approximately 0.167. we still need to add 1 to this, because we are multiplying by that number, not adding that amount of the number. now, we just calculate 4000 * (1.167)^19. use a calculator to get approximately 75232.6, or 75233.

47 - 90 = 43

43 - 180 = x

x = 137