Question

Это как? Помогииитееее

Answer 1

Вот так :

$(p+\frac{p}{d})*(p-\frac{p}{d})=p^{2}-(\frac{p}{d} )^{2} =p^{2} -\frac{p^{2} }{d^{2} }=\frac{p^{2}d^{2} -p^{2}}{d^{2} }=\frac{p^{2}(d^{2} -1)}{d^{2} }$