Verified answer

Решение и ответ:

[tex]\displaystyle {x^5}{x^{12}}={x^{5+12}}={x^{17}}[/tex]

[tex]\displaystyle {40^{20}}\cdot{40^3}={40^{20+3}}={40^{23}}[/tex]

[tex]\displaystyle {\left({\frac{2}{7}}\right)^{31}}\cdot{\left({\frac{2}{7}}\right)^6}={\left({\frac{2}{7}}\right)^{31+6}}={\left({\frac{2}{7}}\right)^{37}}[/tex]

[tex]\displaystyle {\left({-5}\right)^4}\cdot{\left({-5}\right)^{11}}={\left({-5}\right)^{4+11}}={\left({-5}\right)^{15}}[/tex]