You simply plug in the value of x in each equation to find y.
1)
y = 7 - 3(2)
y = 7 - 6
y = 1
2)
y = 18/2
y = 9
hope this helped, blessings!
The tree diagram of the problem above is attached
There are four outcomes of the two events,
First test - Cancer, Second Test - Cancer, the probability is 0.0396
First test - Cancer, Second Test - No Cancer, the probability is 0.0004
First test - No Cancer, Second Test - There is cancer, the probability is 0.0096
First test - No cancer, Second Test - No cancer, the probability is 0.9054
The probability of someone picked at random has cancer given that test result indicates cancer is

The probability of someone picked at random has cancer given that test result indicates no cancer is
Binomial probability states that the probability of x successes on n repeated trials in an experiment which has two possible outcomes can be obtained by
(nCx).(p^x)⋅((1−p)^(n−x))
Where success on an individual trial is represented by p.
In the given question, obtaining heads in a trial is the success whose probability is 1/2.
Probability of 6 heads with 6 trials = (6C6).((1/2)^6).((1/2)^(6–6))
= 1/(2^6)
= 1/64
Answer:
It will be 16/8 I hope you are happy