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Q.
If the equation $(m-n) x^{2}+(n-1) x+1-m=0$ has equal roots, then l, m and $n$ satisfy
Complex Numbers and Quadratic Equations
Solution:
As sum of coefficients is zero, hence one root is 1
and other root is $\frac{l-m}{m-n}$.
Since roots are equal,
$\therefore \frac{1-m}{m-n}=1$
$ \Rightarrow 2 m=n+1$.