i) The point A on a graph is (6,-7), and point B is (3,5). Calculate the equation of the straight line that passes through both A and B. ii) Does the line pass through the point C (-2,26)?
i) Gradient (m) = ∆y/∆x. Therefore: m = (5-(-7))/(3-6) = (12)/(-3) = -4. Intercept (c) = 5-(3*(-4)) = 5+12 = 17. Therefore: y = -4x+17 ii) x = -2, y = 26. -4(-2) + 17 = 25. 25≠26, therefore the line does not pass through C.