If $x_1, x_3$ are the roots of $A x^2-4 x+1=0$ and $x_2, x_4$ are the roots of $B x^2-6 x+1=0$ such that…
If $x_1, x_3$ are the roots of $A x^2-4 x+1=0$ and $x_2, x_4$ are the roots of $B x^2-6 x+1=0$ such that $x_1, x_2, x_3, x_4$ are in harmonic progression, then $\frac{B+A}{B-A}=$