Question

thực hiện phép tính (tính nhanh nếu có thể)

Answer 1

a.

$=(\frac{-17}{13}+\frac{4}{13})+(\frac{11}{31}+\frac{20}{31})+\frac{2}{135}$

$=\frac{-13}{13}+\frac{31}{31}+\frac{2}{135}=(-1)+1+\frac{2}{135}=\frac{2}{135}$

b.

$=(\frac{3}{17}+\frac{20}{-17})+(\frac{4}{18}+\frac{-2}{9})+(\frac{5}{8}+\frac{21}{56})$

$=(\frac{3}{17}+\frac{-20}{17})+(\frac{2}{9}+\frac{-2}{9})+(\frac{5}{8}+\frac{3}{8})$

$=\frac{-17}{17}+\frac{0}{9}+\frac{8}{8}$

$=(-1)+0+1=0$

Answer 2

c.

$=\frac{-5}{12}+\frac{6}{11}+\frac{7}{17}+\frac{5}{11}+\frac{5}{12}$

$=(\frac{-5}{12}+\frac{5}{12})+(\frac{6}{11}+\frac{5}{11})+\frac{7}{17}$

$=\frac{0}{12}+\frac{11}{11}+\frac{7}{17}$

$=0+1+\frac{7}{17}=\frac{24}{17}$

d.

$=\frac{9}{16}+\frac{-8}{27}+1+\frac{7}{16}+\frac{-19}{27}$

$=(\frac{9}{16}+\frac{7}{16})+1+(\frac{-8}{27}+\frac{-19}{27})$

$=\frac{16}{16}+1+\frac{-27}{27}$

$=1+1+(-1)=1$