Question

quanto é -2/5+[-3+(-1/4+1/2)]​

Answer 1

    $-\frac{2}{5}+[-3+(-\frac{1}{4}+\frac{1}{2})]=$

$=-\frac{2}{5}+[-3+(-\frac{1}{4}+\frac{2}{2\times2})]=$

$=-\frac{2}{5}+[-3+(-\frac{1}{4}+\frac{2}{4})]=$

$=-\frac{2}{5}+(-3+\frac{1}{4})=$

$=-\frac{2}{5}+(-\frac{3\times4}{4}+\frac{1}{4})=$

$=-\frac{2}{5}+(-\frac{12}{4}+\frac{1}{4})=$

$=-\frac{2}{5}+(-\frac{11}{4})=$

$=-\frac{2}{5}-\frac{11}{4}=$

$=-\frac{2\times4}{5\times4}-\frac{11\times5}{4\times5}=$

$=-\frac{8}{20}-\frac{55}{20}=$

$=-\frac{63}{20}$