roots a/b, 1/ab
sor = a/b + 1/ab
= (a^2+1 )/ab
por = a/b X 1/ab
= a/ab^2
=1/b^2
form the eq with details pls.
(answer provided is abx^2 -a^2x +1 = 0)
I presume "sor" means "sum of roots" and "por" means "product of roots".
From that, I also presume that you are to create a quadratic equation which has roots as given.
Let $\displaystyle ax^2 + bx + c$ be a quadratic equation.
The sum of roots is $\displaystyle -b/a$ and the product of roots is $\displaystyle c/a$.
(This can be proved from forming the product and sum of the roots as given by the quadratic formula $\displaystyle x = \frac {-b \pm \sqrt {b^2 - 4ac}}{2a}$ and simplifying the expression you get.)
So this gives you $\displaystyle x^2 - \left({\frac {a}{b} + \frac {1}{ab}}\right) + \frac {1}{b^2}$
But if you simplify this equation, you don't get what you've given as the answer.
If you try and solve what your answer provides using the quadratic formula you get:
$\displaystyle x = \frac {a^2 \pm \sqrt {\left({a^2}\right)^2 - 4ab}} {2ab}$
and that's nowhere near an equation giving the above as roots.
So there's either something wrong with the question or it's been copied down wrong.