Step-by-step explanation: the normal format of a linear equation is
y=(slope)x+y intercept. The slope is -6 so y=-6x+y intercept. Plugging in the cordinates, -3=-9(-6)+y intercept. We'll call the y intercept b. -3=54+b. Subtract 54 from both sides of the equation and you get b=-54. The linear equation is
y=-6x-57.
You can check by plugging in x= -9, and y= -3. -3=54-57. -3=-3