Question

Tinh bang cach hop li

a)  \(\left(\frac{1}{4}+\frac{-5}{13}\right)\)+ \(\left(\frac{2}{11}+\frac{-8}{13}+\frac{3}{4}\right)\)

b)\(\left(\frac{21}{31}+\frac{-16}{7}\right)\)+\(\left(\frac{44}{53}+\frac{10}{31}\right)+\frac{9}{53}\)

Answer 1

a)(1/4+3/4)-(5/13+8/13)+2/11=1-1+2/11=2/11

b)(21/31+10/31)-16/7+(44/53+9/53)=1+1-16/7=14/7-16/7=-2/7

Answer 2

bằng2/11

         -16/7

Answer 3

a, \(\left(\frac{1}{4}+\frac{-5}{13}\right)+\left(\frac{2}{11}+\frac{-8}{13}+\frac{3}{4}\right)\)

\(=\left(\frac{1}{4}-\frac{5}{13}\right)+\left(\frac{2}{11}-\frac{8}{13}+\frac{3}{4}\right)\)

\(=\frac{1}{4}-\frac{5}{13}+\frac{2}{11}-\frac{8}{13}+\frac{3}{4}=1-1+\frac{2}{11}=\frac{2}{11}\)( vì \(\left(\frac{1}{4}+\frac{3}{4}\right)+\left(-\frac{5}{13}-\frac{8}{13}+\frac{2}{11}\right)\))

b, \(\left(\frac{21}{31}+\frac{-16}{7}\right)+\left(\frac{44}{53}+\frac{10}{31}\right)+\frac{9}{53}\)

\(=\frac{21}{31}-\frac{16}{7}+\frac{44}{53}+\frac{10}{31}+\frac{9}{53}\)

\(=1-\frac{16}{7}+1=\frac{7}{7}-\frac{16}{7}+\frac{7}{7}=-\frac{2}{7}\)