In mathematics there is a rule of exponents where we can "distribute" the powers/exponents in the numerator and denominator of any expression. Therefore, given an expression as 
, the exponent n can be "distributed" as: 
.
In our case, the power, n=11; a=7 and b=4. Thus, the expression 
, can be written as 
.
Thus, out of the given options, option A is the correct option.
For lesson 4 10^15/10^4= 10^11 because when you are dividing with exponents you have to subtract the bottom exponent with the top one so 15-4=11; 10^15/10^4=10^11
Remark
You have 40 dollars to spend.
<em><u>AT & T</u></em>
Let the number of minutes = M
A. 20 + 0.10*M ≤ 40
B. 20 + 0.10*M ≤ 40 Subtract 20 from both sides.
20 - 20 + 0.10M ≤ 40 - 20
0.10M ≤ 20 Divide by 0.10
0.10M/0.10 ≤20/0.10
M≤ 200 minutes.
Verizon
A
15 + ( M ≥ 300)*0.50 ≤ 40
B
15 + ( M ≥ 300)*0.50 ≤ 40 Subtract 15 from both sides.
(M≥300)*0.50 ≤ 25
(M≥300) ≤ 50 minutes.
This last one is a good deal more complicated. What it means is that if you are under 300 minutes, you pay only 15 dollars. If you are over 300 minutes, you can only go 50 more minutes before over extend your budget.
Part C
These are alike in that they have a flat rate associated with them and both have a budgeted amount that has to be obeyed.
They are quite different in what they offer. The second plan is for people who use their cell phone quite a bit. For people like us (emergency only), the first plan is much better. We would always be within our 40 dollar limit. We don't use our cell but maybe 10 - 15 minutes a month on average.
Part D
I can't answer this for you. It depends on where you live and who offers you the best coverage. I would pick the first one, but that doesn't mean that it would be best for you.
Using addition of variables, it is found that the mean of S is of 73 and the standard deviation is of 8.5.
<h3>What happens to the mean and the standard deviation when two variables are added?</h3>
- The mean is the sum of the means.
- The standard deviation is the square root of the sum of variances.
In this problem, for variables A and B, we have that:
Variable S is the sum of A and B, hence:
The mean of S is of 73 and the standard deviation is of 8.5.
More can be learned about addition of variables at brainly.com/question/26156502
