Answer:
There is a 99.99998% probability that at least one valve opens.
Step-by-step explanation:
For each valve there are only two possible outcomes. Either it opens on demand, or it does not. This means that we use the binomial probability distribution to solve this problem.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinatios of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
In this problem we have that:

Calculate P(at least one valve opens).
This is 
Either no valves open, or at least one does. The sum of the probabilities of these events is decimal 1. So:


So


Finally

There is a 99.99998% probability that at least one valve opens.
Answer:
17
Step-by-step explanation:
AC = AB + BC
Since we know what each variable equals, we can write out the equation as shown:
47 = 5x + 3x - 1
Combining like terms:
47 = 8x - 1
Add 1 on both sides:
48 = 8x
Divide 8 on both sides:
X = 6
Now that we know what X equals, we can solve BC.
BC = 3(6) - 1
BC = 18 - 1
BC = 17
Therefore BC = 17.
The standard form is 21x-y-7=0
Answer:
The domain of a function is defined as the set of x-values for which the function is real and defined. The first alternative is correct
Step-by-step explanation:
Answer:
X = 2
Step-by-step explanation: