Question

$(7\frac{1}{5})^{2} -(2\frac{1}{5}) ^{2}$

Answer 1

Вот, пожалуйста, обращайтесь

Просто возвести в квадрат

Answer 2

$(7\frac{1}{5})^{2}-(2\frac{1}{5})^{2}=(\frac{36}{5})^{2}-(\frac{11}{5})^{2}=(\frac{36}{5}-\frac{11}{5})(\frac{36}{5}+\frac{11}{5} )=(\frac{25}{5})(\frac{47}{5})=47$