Question

A circle is represented by the equation shown below.
(x - 5)2 + (x + 9)2 = 144
Which statement is true?

The circle is centered at (-5, -9) and has a diameter of 12.
The circle is centered at (5, -9) and has a radius of 12.
The circle is centered at (5, 9) and has a diameter of 12.
The circle is centered at (5, 9) and has a radius of 12.

Answer 1

the standard form for the equation of a circle with radius r and center (h, k ) is

\[\large (x-h)^2 + (y-k)^2=r^2 \]

now all you gotta do is match it up with your equation.

Answer 2

i still don't understand. what am i plugging in?

Answer 3

@dpaInc

Answer 4

you don't need to plug in... just match up your equation with the standard equation...