Hey there!
Triangle CBD is congruent to triangle ABD. This means that BD is congruent to BD by reflexive property. You have two congruent angles, and one congruent side. This would be AAS theorem. The answer is D.
I hope this helps!
Let's first write each step of the procedure:
Step 1:
group the x terms together and the terms and together, and move the constant term to the other side of the equation:
x² + 12x + y² + 2y = 1
Step 2:
determine (b ÷ 2) 2 for the x and y terms.
(12 ÷ 2) 2 = 36
and
(2 ÷ 2) 2 = 1
Step 3:
add the values to both sides of the equation.
x2 + 12x + 36 + y2 + 2y + 1 = 1 + 36 + 1
Step 4:
write each trinomial to binomial squared, and simplify the right side.
(x + 6) 2 + (y + 1) 2 = 38
Answer:
the last step is:
(x + 6) 2 + (y + 1) 2 = 38
Answer:


And using a calculator, excel ir the normal standard table we have that:

And we can calculate the probability like this:
Step-by-step explanation:
A random sample of 36 observations has been drawn from a normal distribution with mean 50 and standard deviation 12. Find the probability that the sample mean is in the interval 47<=X<53. Is the assumption of normality important. Why?
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where
and 
Since the distribution for X is normal then we know that the distribution for the sample mean
is given by:

We can find the probability required like this:


And using a calculator, excel ir the normal standard table we have that:

And we can calculate the probability like this:

Answer:
Jones family paid a total of $139
Step-by-step explanation:
Smith's Mountain Lake Boat provides Rental services that can be expressed as follows;
Total cost=cost per hour×number of hours rented+one time cleaning deal
For Benael's family;
Benael family total cost=Cost per hour×number of hours rented+one-time cleaning deal
where;
Benael family total cost=$226.50
Cost per hour=$25
Number of hours rented=11 am-6:30 pm=7 hours 30 minutes=7.5 hours
One time cleaning deal=x
Replacing;
226.50=(25×7.5)+x
187.5+x=226.50
x=226.50-187.5
x=39
One time cleaning deal=$39
For Jones family;
Jones family total cost=Cost per hour×number of hours rented+one-time cleaning deal
where;
Cost per hour=$25
Number of hours rented=9 am-1 pm=4 hours
One time cleaning deal=$39
Replacing;
Jones family total cost=(25×4)+39
Jones family total cost=$139
Jones family paid a total of $139
∑ from 1 to infinity of 12(3/5)^(i - 1)
Since the common ratio is less than 1, the series is convegent. [i.e. 3/5 < 1]
Sum to infinity of a geometric series is given by a/(1 - r); where a is the first term, and r is the common ratio.
Sum = 12/(1 - 3/5) = 12/(2/5) = 30.