12x - 18 - 4x -2
12x - 4x = 8x (yours 12x - 4x = 8)
-18 - 2 = -20 (yours -18 -1 = 17)
answer:
8x - 20
Answer:
B
Step-by-step explanation:
Hi there!
TL;DR: Observe the vertices of the shapes inside the circles and their relationship with the circle.
For the first figure, the rectangle has 4 vertices and there are 4 dots on the perimeter of the circle.
For the second figure, the triangle has 3 vertices and there are 3 dots on the perimeter of the circle.
For the third figure, the line has 2 points and there are 2 dots on the perimeter of the circle.
For the fourth figure, there would most likely be only one dot on the perimeter of the circle (4, 3, 2, 1). The only option that shows this is B.
I hope this helps!
Answer:
![(x+8)^2 +(y-4)^2 = 25](https://tex.z-dn.net/?f=%20%28x%2B8%29%5E2%20%2B%28y-4%29%5E2%20%3D%2025)
Step-by-step explanation:
Assuming this complete problem: "A cell tower is located at (-8, 4) and transmits a circular signal that covers three major cities. The three cities are located on the circle and have the following coordinates: G (-4, 7), H (-13, 4), and I (-8, -1). Find the equation of the circle"
For this case the generla equation for the circle is given by:
![(x-h)^2 +(y-k)^2 = r^2](https://tex.z-dn.net/?f=%20%28x-h%29%5E2%20%2B%28y-k%29%5E2%20%3D%20r%5E2)
From the info we know that the tower is located at (-8, 4) so then h = -8 and k = 4, so then we need to find the radius. So we have the equation like this:![(x+8)^2 +(y-4)^2 = r^2](https://tex.z-dn.net/?f=%20%28x%2B8%29%5E2%20%2B%28y-4%29%5E2%20%3D%20r%5E2)
If the 3 points are on the circle then satisfy the equation. We can use the first point (-4,7) and if we replace we can find the value for ![r^2](https://tex.z-dn.net/?f=r%5E2)
![(-4+8)^2 +(7-4)^2 =25= r^2](https://tex.z-dn.net/?f=%20%28-4%2B8%29%5E2%20%2B%287-4%29%5E2%20%3D25%3D%20r%5E2)
So then ![r = \sqrt{25}=5](https://tex.z-dn.net/?f=%20r%20%3D%20%5Csqrt%7B25%7D%3D5)
And if we replace the second point we got this:
![(-13+8)^2 +(4-4)^2 = 25 =r^2](https://tex.z-dn.net/?f=%20%28-13%2B8%29%5E2%20%2B%284-4%29%5E2%20%3D%2025%20%3Dr%5E2)
And for the third point we have:
![(-8+8)^2 +(-1-4)^2 = 25 =r^2](https://tex.z-dn.net/?f=%20%28-8%2B8%29%5E2%20%2B%28-1-4%29%5E2%20%3D%2025%20%3Dr%5E2)
And we got the same result.
So then our final equation is given:
![(x+8)^2 +(y-4)^2 = 25](https://tex.z-dn.net/?f=%20%28x%2B8%29%5E2%20%2B%28y-4%29%5E2%20%3D%2025)
the opposite or addictive increase of 5x is -5x.
the opposite or addictive increase of 5x + 8 is -5x -8.