Find k so that x + 2 is a factor of x ^ 3 - k * x ^ 2 + 2x + 7k. (If anyone could help me out with this that would be amazing!!)

k = 4

Step-by-step explanation:

If x + 2 is a factor of the polynomial;

By the factor theorem, if we set x + 2 = 0, then make x the subject of the formula; if we substitute the value into the polynomial, the result we should have after calculating should be zero

So, we have it that;

x + 2 = 0

x = -2

Substitute into the polynomial and equate to zero

(-2)^3 - k (-2)^2 + 2(-2) + 7k = 0

-8 -4k -4 + 7k = 0

-12 -4k + 7k = 0

-12 + 3k = 0

-3k = -12

k = -12/-3

k = 4

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.