Answer:
Step-by-step explanation:
Standard form of a circle is given by,
(x - a)² + (y - b)² = r²
Here, (a, b) is the center and 'r' is the radius of the circle.
For a circle having center (8, -4) and radius r = 1
Equation of the circle will be,
(x - 8)² + (y + 4)² = 1²
(x - 8)² + (y + 4)² = 1
Option (1) is the answer.
Question (2)
Circle with the center (-1, 0) and a point (2, -4) on it,
Radius of the circle = Distance between the center and the given point on circumference
= 
= 
= 
= 5
Therefore, equation of the circle will be,
(x + 1)² + (y - 0)² = 5²
(x + 1)² + y² = 25
Answer:
x=6,y= 7
Step-by-step explanation:
-6x +7y= 13
-6x+8y=20
-y = -7
divide through by -1
y =7
sub y= 7 in equation 1
then x= 6
Answer:
See below:
Step-by-step explanation:
Hello! We can check to see if the inequality is true by replacing r with 18 as we have been told to find them in which 18 as r makes the equation true.
So our equations to test for are:

We can input 18 as r and then we see the following are correct:
1. No, as a -21 is not greater than -6
2. Yes, as -15 is less than 6.
3. No, as 21 is not greater than 6
4. No, as -15 is not greater than 6.
Cheers!
Answer:
-2
Step-by-step explanation:
3x isnt used because it stated when x>1.
so -2(1) is -2, because x =< 1 is true