Question

*Fill in the blanks with the correct letters* (You don't have to explain it I just need the answers please)

The general form of the equation of a circle is
7x^2 + 7y^2 - 28x + 42y - 35 = 0.

The equation of this circle in standard form is ___.

A. (x - 2)^2 + (y + 3)^2 = 5
B. (x - 2)^2 + (y + 3)^2 = 18
C. (x - 4)^2 + (y + 6)^2 = 24
D. (x + 4)^2 + (y - 6)^2 = 24
E. (x + 2)^2 + (y - 3)^2 = 35

The center of the circle is at the point __

A. (-14,21)
B. (-2,3)
C. (2,-3)
D. (-4,6)
E. (4,-6)

And it's radius is ___ units.

A. 5 1/2
B. 3(2 1/2)
C. 2(6 1/2)
D. 35 1/2

Answer 1

7x^2 + 7y^2 - 28x + 42y - 35 = 0.
⇒ x^2 + y^2 - 4x + 6y - 5 = 0.
⇒ (x-2)^2 + (y+3)^2 = 18

1. B
2. C
3. B