Answer:
1. x = - 1 -y over 2
2. x = -4(2+y) over 3
Step-by-step explanation:
Answer:




Step-by-step explanation:
The probability mass function P(X = x) is the probability that X happens x times.
When n trials happen, for each
, the probability mass function is given by:

In which p is the probability that the event happens.
is the permutation of n elements with x repetitions(when there are multiple events happening(like one passes and two not passing)). It can be calculated by the following formula:

The sum of all P(X=x) must be 1.
In this problem
We have 3 trials, so 
The probability that a wafer pass a test is 0.7, so 
Determine the probability mass function of the number of wafers from a lot that pass the test.




The answer is B, the answer is 9,318,000= 9.318•10 to the 6th power
By HA (hypotenuse is the same and angles are equal)