Once you know $x$, plug that value into $y=(x+5)^2$ to compute $y$.

When you square a number, the result is always nonnegative. Make sure you add inside the parentheses first, then square the result.

In the first expression line, type y = 3x + 6. Look at where this line crosses the $x$-axis (the $x$-intercept). Tap that point; the $x$-coordinate is the solution to $3x+6=0$.

In a new expression line, type y = (x + 5)^2 to graph the parabola that represents the second equation.

Take the $x$-value you found from the $x$-intercept in step 1 and type a vertical line with that value (for example, if it was $a$, type x = a). The intersection of this vertical line with the parabola y = (x + 5)^2 gives a point whose coordinates $(x, y)$ satisfy the system. Read both coordinates from Desmos.

Use the first equation:

Subtract 6 from both sides:

Divide both sides by 3:

So any solution to the system must have $x=-2$.

Now use the second equation:

Substitute $x=-2$:

So any solution to the system must have $y=9$ when $x=-2$.

We found $x=-2$ and $y=9$, so the ordered pair that satisfies both equations is $(-2, 9)$, which corresponds to choice C.