The weeks and loads of waste removed serve as the x and y coordinates in the equation you're looking for. Using the coordinates, you can find the slope of the line and then use that slope along with ONE of the coordinates to solve for b, the y-intercept. Use the general linear formula: y = mx + b, where m is the slope and b is the y-intercept. Using the coordinates find the slope:y2 - y1/x2 - x1. Our particular coordinates look like this in that formula: 30-40/10-5 is a slope of -2. Now that we have the slope, use one of the coordinates to solve for b, the y intercept: 30 = -2(10) + b. That is subbing in the x value and the y value of one of the coordinates into the linear form of the equation, leaving us to solve for b. 30 = -20 + b and b = 50. So filling that in along with our slope gives us a line of y = -2x + 50. And that's the equation.
