Question

If $l,m,n$ are real, $l\ne m$, then the roots of the equation $(l-m)x^2-5(l+m)x-2(l-m)=0$ are

• A. real and equal
• B. complex
• C. real and unequal
• D. none of these

Answer 1

Answer: (C)

real and unequal

Given, $(l-m)x^2-5(l+m)x-2(l-m)=0$

The standard quadratic equation is $a{x}^2+bx+c=0$

here, $D=b^2-4ac=25{(l+m)}^2+8{(l-m)}^2>0$

Therefore, the roots are real and unequal.
Ans: C