A straight line passes through the points (-2, 4) and (1, 10). What is (a) the gradient of the line, (b) the y-intercept of the line and (c) the equation of the line?
(a) Gradient (m) = (y2-y1)/(x2-x1) = (10-4)/(1-(-2)) = 6/3 = 2
(b) General equation of a straight line: y = mx + c (c = y-intercept)
For our straight line: y = 2x + c
Test points: 4 = 2(-2) + c ---> c = 8
(c) General equation of our straight line: y = 2x + 8
