Answer:
x = 3
Step-by-step explanation:
The given slope and point can be used to write the equation of the line using the point-slope form. To find x for a given y, we can solve that equation.
__
<h3>setup</h3>
The point-slope form of the equation for a line is ...
y -k = m(x -h) . . . . . . line with slope m through point (h, k)
For (h, k) = (-3, 0), and m = -1, the equation is ...
y -0 = -1(x -(-3))
y = -x -3
We want x when y = -6, so this becomes ...
-6 = -x -3
<h3>solution</h3>
Adding x+6 to both sides of the equation, we get ...
(x +6) -6 = -x -3 +(x +6)
x = 3 . . . . . . . simplify