Answer: x = -1 and y = -2
Step-by-step explanation:
So if you know y = x-1 you can plug that in where y is in the first equation
-4x + 3(x-1) = -2
Distribute the 3:
-4x +3x -3 = -2
Combine like terms:
-x -3 = -2
Add 3 to both sides:
-x = 1
Multiply by -1:
X = -1
Then you plug that into the other equation to get y=(-1)-1
Which is -2
Using the normal distribution, it is found that there is a 0.0005 = 0.05% probability of getting more than 66 heads.
<h3>Normal Probability Distribution</h3>
The z-score of a measure X of a normally distributed variable with mean
and standard deviation
is given by:

- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
- The binomial distribution is the probability of x successes on n trials, with p probability of a success on each trial. It can be approximated to the normal distribution with
.
For the binomial distribution, the parameters are given as follows:
n = 100, p = 0.5.
Hence the mean and the standard deviation of the approximation are given as follows:
.
Using continuity correction, the probability of getting more than 66 heads is P(X > 66 + 0.5) = P(X > 66.5), which is <u>one subtracted by the p-value of Z when X = 66.5</u>.


Z = 3.3
Z = 3.3 has a p-value of 0.9995.
1 - 0.9995 = 0.0005.
0.0005 = 0.05%
More can be learned about the normal distribution at brainly.com/question/4079902
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Answer:

Step-by-step explanation:
Let's find our C value for the quadratic equation.

That is our C. Since we added 9 to one side, we have to do the same to the other. We get:

Now, lets form the left side as a binomial squared.

Let's square both sides now:

Now, we subtract 3 from both sides to isolate the variable, X:

This means that the answers are:

I do not understand your answers though. Answer A makes no sense, answer B is 221, answer C is 115, and answer D also does not make sense. If you could clarify this portion, maybe I can help you find your alphabetic answer
Total points scored=72(2)+9
=153
Mean=153/7
=21 6/7
=21.9 (3s.f.)