What is the length of a radius of the circle represented by the equation x2 + y2 - 4x - 4y + 4 = 0?

A) 2 units

B) 4 units

C) 8 units

D) 16 units

A) 2 units

Step-by-step explanation:

Given;

x² + y² - 4x - 4y + 4 = 0

Consider general circle equation;

(x - h)² + (y - k)² = r²

where;

(h , k ) is the center of the circle

r is the radius of the circle

x² + y² - 4x - 4y + 4 = 0

subtract 4 from both sides of the equation

x² + y² - 4x - 4y  =  - 4

square half of coefficient of x and y, and add them to both sides of the equation

x² +  - 4x + (-2)² +  y² - 4y + (-2)² = - 4 +  (-2)² +  (-2)²

factorize x and y

(x - 2)² + (y - 2)² = - 4 + 4 + 4

(x - 2)² + (y - 2)² = 4

(x - 2)² + (y - 2)² = 2²

Compare this final equation to general equation of a circle

(x - 2)² + (y - 2)² = 2²  

(x - h)² + (y - k)² = r²

r = 2

Thus, the length of a radius of the circle is 2 units

to determine the unit cost your would divide the total cost by the number sold.

7 bagels for $4.41       $4.41/7 = $.63 each at fresh side

5 bagels for $3.60         $3.60/5 = $.72 each at value mart

hi there!

step-by-step explanation:

a roof pitch is basically for every inch rise there is 12 inches run.

the height of the roof is also known as the rafter.

formula: rafter^2 = rise^2 + run^2

rafter^2 = 5^2 + 12^2

rafter^2 = 25 + 144

rafter ^2 = 169"^2

the height of the roof from the lowest point to the highest point is 169"^2.

hope this : )