The point C (–1,2) divides the line segment AB in the ratio 3:4, where the coordinates of A is (2, 5). The coordinates of B are___________.
(–5, –2)
If a point P(x,y) divides a line segment joining (x1,y1) and (x2,y2) in the ratio m:n, then the coordinates of P are given by:
x=mx2+nx1m+n, y=my2+ny1m+n
Let C(−1,2) divide the line joining A(2,5) and B(x,y) in the ratio 3:4.
Then,
C(3x+87,3y+207) = C(-1, 2)
⇒3x+87=−13x+8=−7⇒x=−5 ⇒3y+207=23y+20=14⇒y=−2
Thus, the coordinates of B are B(−5,−2).