Question

How to find the center and radius of `(x+4)^2+y^2=49`?

Answer 1

center: `(-4,0)`
radius: `7`

Explanation:

The general form for the equation of a circle is
`color(white)("XXX")(x-a)^2+(y-b)^2=r^2` for a circle with center `(a,b)` and radius `r`

Given
`color(white)("XXX")(x+4)^2+y^2=49`

Re-arranging into the general form for a circle:
`color(white)("XXX")(x-(-4))^2+(y-0)^2=7^2`