Step 1) Write out the general equation of a straight line: y = mx + c where m is the gradient and c is where the line intersects the y-axis. Step 2) Find the gradient: m = change in y / change in x, m = (-11-4) / (7-2), m = -15 / 5 m = -3 Step 3) Find c: This can be done by substituting in co-ordinates of either of the points that the line passes through into the equation y = -3x + c, 4 = -3*2 + c, c = 10 Step 4) Write out the equation: y = -3x + 10