X/4 + y/5 = 2 and x/2 + y = - 3. Solve for x and y

A) x/4 + y/5 = 2

B) x/2 + y = - 3

Step-by-step explanation:

We multiply A) by -4 and B) by 2

A) -x - 4/5 y = -8

B) x + 2y = -6 then add A) and B)

1.2y = -14

y = 11 (2/3) = -11.6666666...

x + 2y  = -6

x = -6 -2*-11.6666666

x =  -23.3333332

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! )