Write the 2 equations:
5x-2y=18
-5x+3y=-22
You can see that the coefficients of x are opposites, so you can add them(the 2 equations) to eliminate x.
Adding them, you get:
y=-3
So now that you know y, you can substitute the value of y into one of the original equations. Let's substitute it in the first one:
5x+6=18
Solving this, we get:
5x=12
x=12/5
x=12/5, y=-3
Answer:
5
Step-by-step explanation:
<em>35/7=5 </em>
A: 0 3 4 5 5 6 7 9 9 20
3 3 5 5 6 8 8 9 9
B: No, they are not symmetric
Answer:
Question 1:
(b) 4,445
Question 2:
(c) 2.1%
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of
, and a confidence level of
, we have the following confidence interval of proportions.

In which
z is the zscore that has a pvalue of
.
The margin of error is of:

95% confidence level
So
, z is the value of Z that has a pvalue of
, so
.
Question 1:
We have no previous estimate for the population proportion, so we use
.
The sample size is n for which M = 0.015. So






Samples above this value should be used, and the smaller sample above this value is of 4445, so the answer is given by option b.
Question 2:
Now we find M for which
.



So 2.1%, and the correct answer is given by option c.