Here is the equation of a circle: x2 + y2 - 6x - 20y + 105 = 0 Elena wants to find the center and radius of the circle. Here is what she's done so far.
Step 1: x2 - 6x + y2 – 20y = -105
Step 2: x2 - 6x + 9+ y2 - 20y + 100 = -105 + 9 + 100
Step 3: x2 - 6x + 9 + y2 - 20y + 100 = 4
1. What did Elena do in the first step?
2. Why did Elena add 9 and 100 to the left side of the equation in Step 2?
3. Why did Elena add 9 and 100 to the right side of the equation in Step 2?
4. What should Elena do next?

1. 3

2. 4

3. 1

hope this ! have a great day.

-wfz

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b

answer: the distance

step-by-step explanation:

to calculate the distance d of a line segment with endpoints (x1, y1) and (x2, y2) use the formula d (x2 x1)2 (y2 y1)2. to calculate the midpoint of a line segment with endpoints (x1, y1) and (x2, y2) use the formula