Solve for x x-xy=z Hint: reverse distribution to get x alone

Work Shown:

x - xy = z

x*1 - x*y = z

x*(1 - y) = z distributive rule in reverse

x = z/(1-y) divide both sides by (1-y)

The distributive rule is a*(b+c) = a*b+a*c. You can also say a*(b-c) = a*b-a*c. In this case, we factored out the common factor x.

the answer   is 200

step-by-step explanation:

this is a problem about poisson probabilities.   i don't know if you've

already studied poisson distributions, or if you have a place to look

to read more about the subject.  

here's how you can see a poisson distribution coming.   when there are

a lot of events that may happen at any time (or any place), and when

you're counting how many of them happen at a particular time (or a

particular place), and each event is independent of the others, then

the result is a poisson distribution.   this is roughly true for the

chocolate chips; one chip being in a cookie has only a small effect on

the probability that another chip will be in the cookie.

once you know you have a poisson distribution, you know a lot.   there

is only one parameter to a poisson distribution, so if you know the

mean, you know everything.   the form of the distribution is

  probability of n chips = {[e^(-x)]*(x^n)} / (n! )

step-by-step explanation:

the answer is 128