Answer
$\\(x+4)^2+y^2=100$
Work Step by Step
RECALL:
The standard form of the equation of a circle with a center of $(h, k)$ and a radius of $r$ units is:
$(x-h)^2 + (y-k)^2 = r^2$
The given circle has its center at $(-4, 0)$ and a radius of $10$ units.
Use the standard form above where $h=-4$, $k=0$, and $r=10$ to obtain:
$[x-(-4)]^2 + (y-0)^2 =10^2
\\(x+4)^2+y^2=100$