(a)The points A(8, −4) and B(−1, 3) are the endpoints of the line segment [AB]. Find the coordinates of the point C, which divides [AB] internally in the ratio 4 : 1.
(b)The line l has a slope of m and contains the point (q, r), where m, q, r ∈ ℝ are all positive. Find the co-ordinates of the point where l cuts the y-axis, in terms of m, q, and r.
(c)The line k has a slope of −2. The line j makes an angle of 30° with k. Find one possible value of the slope of the line j. Give your answer in the form d + e√f, where d, e, f ∈ ℤ.