Two sides of a rhombus are along the lines, x - y + 1 = 0 and 7x - y - 5 = 0. If its diagonals intersect at (-1, -2), then which one of the following is a vertex of this rhombus ?
Point of intersection of sides
x – y + 1 = 0
and 7x – y – 5 = 0
∴x=1,y=2
Slope of AM =42=2
∴ Equation of BD :y+2=−12(x+1)
⇒x+2y+5=0
Solving x + 2y + 5 = 0 and 7x – y – 5 = 0
x=13,y=−83⇒(13,−83)