In what ratio, the line joining (–1, 1) and (5, 7) is divided by the line x + y = 4?


The equation of the line joining the points are (-1,1) and (5, 7) is given by




x – y + 2 = 0 ---------- (1)


The equation of the given line by


x + y – 4= 0 -----------(2)


The point of intersection of lines (1) and (2) is given by x = 1 and y = 3.


Let points (1,3) divide the line segment joining (-1,1) and (5,7) in the ratio 1: k.


Thus, by using section formula, we get,





Thus,


-k + 5 = 1+ k


2k = 4


k = 2


Therefore, the line joining the points (-1, 1) and (5, 7) is divided by line


x + y = 4 in the ratio 1: 2.


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