Answer:
Explanation:
19.
P = 2(x - 3 + 7x + 1)
= 2(8x - 2)
= 16x - 4
20.
P = 3y + 5 + y - 4 + 6y
= 10y + 1
Answer:
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First, combine 20c and 10c because they are like terms then combine 8d and -5d.
It would look like this:
20c+8d+10c-5d
30c+3d
Hope that helps
The equation of the rotating light is an illustration of a secant function
The equation that represents the distance between the center of the circle and the light source is 
<h3>How to determine the equation</h3>
The equation is a secant function represented by

Where:
A represents the amplitude
So, we have:
--- the distance of the light from each square wall
B represents the period, and it is calculated as:

The light completes its full rotation every 6 seconds.
This means that,
T = 6
So, we have:

Simplify

Substitute values for A and B in 

Rewrite as a function

Hence, the equation that represents the distance between the center of the circle and the light source is 
Read more about trigonometry functions at:
brainly.com/question/1143565
Given:
4:x::x:16
To find:
The value of x.
Solution:
We have,
4:x::x:16
It means, we have
4:x = x:16
It can be rewritten as

On cross multiplication, we get


Taking square root on both sides.


Since ratio can be negative or positive, therefore, the value of x is either -8 or 8.