If you need to form the equation for this line, we should first understand Slope Intercept Form (SIF). SIF is y=mx+b where m is our slope and b is our y-intercept (the value of y when x=0).
We already know our slope, so at this point the equation is y=-6x+b. Now we must find our y-intercept, which we can do by plotting the given point and following the slope, which shows up our slope is -23. This means our final equation is y=-6x-23.
Below, I have attached a graph to help you visualize this. Please note that each box is 2 units. The highlighted area represents the y-intercept, while the blue circle represents our original given point. The green dots show our slope.