First we need to convert the given equation to standard form, only then we can find the center and radius of the circle.
![x^{2} + y^{2} +18x+14y+105=0 \\ \\ x^{2} +18x+ y^{2}+14y=-105 \\ \\ x^{2} +2(x)(9)+ y^{2}+2(y)(7)=-105 \\ \\ x^{2} +2(x)(9)+ 9^{2} + [y^{2}+2(y)(7)+7^{2}] =-105+9^{2}+7^{2} \\ \\ (x+9)^{2}+ (y+7)^{2}=25 ](https://tex.z-dn.net/?f=%20x%5E%7B2%7D%20%2B%20y%5E%7B2%7D%20%2B18x%2B14y%2B105%3D0%20%5C%5C%20%20%5C%5C%20%0A%20x%5E%7B2%7D%20%2B18x%2B%20y%5E%7B2%7D%2B14y%3D-105%20%5C%5C%20%20%5C%5C%20%0A%20x%5E%7B2%7D%20%2B2%28x%29%289%29%2B%20y%5E%7B2%7D%2B2%28y%29%287%29%3D-105%20%5C%5C%20%20%5C%5C%20%0Ax%5E%7B2%7D%20%2B2%28x%29%289%29%2B%209%5E%7B2%7D%20%2B%20%5By%5E%7B2%7D%2B2%28y%29%287%29%2B7%5E%7B2%7D%5D%20%20%3D-105%2B9%5E%7B2%7D%2B7%5E%7B2%7D%20%20%5C%5C%20%20%5C%5C%20%0A%20%28x%2B9%29%5E%7B2%7D%2B%20%28y%2B7%29%5E%7B2%7D%3D25%20%20%0A%20%20)
The standard equation of circle is:

with center (a,b) and radius = r
Comparing our equation to above equation, we can write
Center of circle is (-9, -7) and radius of the given circle is 5
An hour has 60 minutes.
-> 5/6 of 60 minutes
5/6*60
=50
So, 50 minutes
-> 1/2 of 60 minutes
1/2*60
=30
So, 30 minutes
-> 2/3 of 60 minutes
2/3*60
=40
So, 40 minutes.
Hope this helps. If you have any questions, please put them in the comments below.
Answer:

Step-by-step explanation:
Given that the triangles are similar then the ratios of corresponding sides are equal.
To determine the scale factor calculate the ratio of corresponding sides, that is
=
= 
x y
------ -----
-9 -2
-5 -7
-1 -12
3 -17
ur x's all have a difference of 4, and ur y's all have a difference of -5...so yes, this is linear with a slope of (-7+2) / (-5 + 9) = -5/4