Tìm p biết: (x + y)^2 / (x - y) = p / (x^2 - y^2)

\(\frac{{{{\left( {x + y} \right)}^2}}}{{x - y}} = \frac{p}{{{x^2} - {y^2}}}\)

\(\frac{{{{\left( {x + y} \right)}^2}}}{{x - y}} = \frac{p}{{\left( {x - y} \right)\left( {x + y} \right)}}\)

\(\frac{{{{\left( {x + y} \right)}^3}}}{{\left( {x - y} \right)\left( {x + y} \right)}} = \frac{p}{{\left( {x - y} \right)\left( {x + y} \right)}}\)

Suy ra: p = (x + y)³.