Answer:
I'm am pretty sure that the answer is 320. Hope this helps!
For the given geometric series the value of the common ratio(r) is 3, while the value of a₁ is 1.
<h3>What is geometric series?</h3>
A series of numbers whose any two consecutive numbers are always in a common ratio of that series.
Given to us
Series, 1 3 9 27 81
To find the value of the common ratio(r), we will simply find the ratio of any two consecutive numbers, therefore,

As we can see the common ratio of the given series is 3, therefore, every next number will be thrice the number before.
We need to find the value of a₁ for the given series, and as we know that a₁ is the first number of the series with which the series is starting, therefore,
a₁ = 1
Hence, for the given geometric series the value of the common ratio(r) is 3, while the value of a₁ is 1.
Learn More about Geometric Series:
brainly.com/question/14320920
Turn the text into an eqation:
48-x = 4x-7
5x = 55
x = 11
Question:
Consider ΔABC, whose vertices are A (2, 1), B (3, 3), and C (1, 6); let the line segment AC represent the base of the triangle.
(a) Find the equation of the line passing through B and perpendicular to the line AC
(b) Let the point of intersection of line AC with the line you found in part A be point D. Find the coordinates of point D.
Answer:


Step-by-step explanation:
Given




Solving (a): Line that passes through B, perpendicular to AC.
First, calculate the slope of AC

Where:
--- 
--- 
The slope is:



The slope of the line that passes through B is calculated as:
--- because it is perpendicular to AC.
So, we have:


The equation of the line is the calculated using:

Where:

--- 

So, we have:

Cross multiply




Make y the subject

Solving (b): Point of intersection between AC and 
First, calculate the equation of AC using:

Where:
--- 

So:



So, we have:
and 
Equate both to solve for x
i.e.


Collect like terms

Multiply through by 5

Collect like terms

Solve for x


Substitute
in 


Take LCM


Hence, the coordinates of D is:
