Please answer the following questions

Problem N1 (a). A system of six linear equations with five unknowns 71, 12, 13, T4, Is has two solutions (T1, 12, 13, 14, IS) = (1, 2, 3, 4, 5) and (T1, 12. 13. TA, IS) = (7, 8.9, 10, 11) . Find a solution (71, 12. 13, 14, x5) of this system such that r = 19. [Marks= 5] (b). Three points A. B. C in R' are given: 4 - (1. 2.3). B - (2.2. -1). C - (3.1,0). Find the coordinates of the point D Iving on the line passing through A and B such that the vector C'D is orthogonal to the vector AB. [Marks= 5]