question_answer

Two sides of a rhombus are along the lines, \[x-y+1=0\] and \[7x-y-5=\text{0}\]. If its diagonals intersect at \[\left( -\,1,-\,2 \right),\] then which one of the following is a vertex of this rhombus?

A)  \[\left( -\,3,-\,8 \right)\]               

B)  \[\left( \frac{1}{3},-\frac{8}{3} \right)\]

C)  \[\left( -\frac{10}{3},-\frac{7}{3} \right)\]            

D)  \[\left( -\,3,-\,9 \right)\]

E)  None of these