Answer:
x^{2} +2x+y^{2}+2y= 18
Step-by-step explanation:
equation of circle is:

using distance formula and substituting value,

solving,
r=
for equation of circle,

on solving,

on solving,

4/5 is the answer.
The formula is y=mx+b, where m is the slope
Answer:

Step-by-step explanation:
Given:

Find first terms:

In this arithmatic sequence, each next term is 1 less than the previous term.
The general explicit formula is

In your case,

Then

It is 800 because the 4 can not tell the what to do so that it is