R is the mid point of qs it means qr = rs and qs = qr + rs it seems s is the mid point of rt it means rs = st and rt = rs+st putting the values of rt, rs and st and solve for x 8x-43 = 2x -4 + 4x-1 8x-4x-2x = 43-5 2x = 38 x = 19 Now rs = 2x-4 = 2 x 19 -4 = 38 - 4 = 34 = qr and qs = rs + qr = 34 + 34 = 68