Question

решите эти примеры, плиииз​

Answer 1

Ответ:

$\frac{1}{3}; 8;$

Пошаговое объяснение:

$1. \frac{5(a^{2}+2ab+b^{2})}{3(a^{3}+3a^{2}b+3ab^{2}+b^{3})}=\frac{5(a+b)^{2}}{3(a+b)^{3}}=\frac{5}{3(a+b)};$

$a=-2,5, b=7,5;$

$\frac{5}{3(-2,5+7,5)}=\frac{5}{3*5}=\frac{1}{3};$

$2. \frac{2(x+y)(x^{2}-xy+y^{2})}{(x^{3}-y^{3})(x^{3}+y^{3})}=\frac{2(x+y)(x^{2}-xy+y^{2})}{(x^{3}-y^{3})(x+y)(x^{2}-xy+y^{2})}=\frac{2}{x^{3}-y^{3}};$

$x=\frac{1}{2},y=-\frac{1}{2};$

$\frac{2}{(\frac{1}{2})^{3}-(-\frac{1}{2})^{3}}=\frac{2}{\frac{1}{8}-(-\frac{1}{8})}=\frac{2}{\frac{1}{8}+\frac{1}{8}}=\frac{2}{\frac{1}{4}}=2*4=8;$