Question

Calcule o valor das expressões numéricas:

Answer 1

$1-[-2-(- \frac{6}{5}+2)+ \frac{1}{2}]+ \frac{1}{4}=\\1-[-2- \frac{4}{5}+ \frac{1}{2}]+ \frac{1}{4}=\\1-[- \frac{14}{5}+ \frac{1}{2}]+ \frac{1}{4}=\\1-[- \frac{23}{10}]+ \frac{1}{4}=\\1+ \frac{23}{10}+ \frac{1}{4}=\\ \frac{33}{10}+ \frac{1}{4}=\\ \frac{142}{40}=\\ \frac{71}{20}$

ou

$1-[-2-(- \frac{6}{5}+2)+ \frac{1}{2}]+ \frac{1}{4}=\\1-[-2-(-1,2+2)+0,5]+0,25=\\1-[-2-(0,8)+0,5]+0,25=\\1-[-2-0,8+0,5]+0,25=\\1-[-2,8+0,5]+0,25=\\1-[-2,3]+0,25=\\1+2,3+0,25=\\3,3+0,25=\\3,55=\\ \frac{355}{100}=\\ \frac{71}{20}$

$\frac{1}{4}+[-0,6-(-2+ \frac{7}{5})+(- \frac{1}{2}+1,4)]=\\ \frac{1}{4}+[- \frac{6}{10}-(- \frac{3}{5})+(- \frac{1}{2}+ \frac{14}{10})]=\\ \frac{1}{4}+[- \frac{3}{5}+ \frac{3}{5}+( \frac{9}{10})]=\\ \frac{1}{4}+ \frac{9}{10}=\\ \frac{23}{20}$

Ou

$\frac{1}{4}+[-0,6-(-2+ \frac{7}{5})+(- \frac{1}{2}+1,4)]=\\0,25+[(-0,6-(-2+1,4)+(-0,5+1,4)]=\\0,25+[(-0,6-(-0,6)+(0,9)]=\\0,25+[(-0,6+0,6+0,9)]=\\0,25+[0,9]=\\0,25+0,9=\\1,15=\\ \frac{115}{100}=\\ \frac{23}{20}$