a) -3/17+(2/3+3/17)=-3/17+2/3+3/17=2/3

b)(-5/7-2/7)+(3/4+1/4)-1/5=(-1)+1-1/5=-1/5

 bài 2

a) 7/6:x=4/5-1/6

    7/6:x=19/30

  x=19/30*7/6=133/180

Bài 1:

$a, \frac{-3}{17}+ (\frac{2}{3}+\frac{3}{17})$

$=\frac{-3}{17}+ \frac{2}{3}+\frac{3}{17}$

$=(\frac{-3}{17}+\frac{3}{17}) +\frac{2}{3}$

$=0 +\frac{2}{3}=\frac{2}{3}$

$b, \frac{-5}{7}+\frac{3}{4}+\frac{-1}{5}+\frac{-2}{7}+\frac{1}{4}$

$=(\frac{-5}{7}+\frac{-2}{7})+(\frac{3}{4}+\frac{1}{4})+\frac{-1}{5}$ 

$=-1 + 1+\frac{-1}{5}=\frac{-1}{5}$ 

Bài 2:

$\frac{3}{1·4}+\frac{3}{4·7}+\frac{3}{7·10}+\frac{3}{10·13}+\frac{3}{13·17}$ 

$=\frac{3}{1}-\frac{3}{4}+\frac{3}{4}-\frac{3}{7}+\frac{3}{7}$

$-\frac{3}{10}+\frac{3}{10}-\frac{3}{13}+\frac{3}{13}-\frac{3}{17}$

$=\frac{3}{1}+(-\frac{3}{4}+\frac{3}{4})+(-\frac{3}{7}+\frac{3}{7})+$

$(-\frac{3}{10}+\frac{3}{10})+(-\frac{3}{13}+\frac{3}{13})-\frac{3}{17}$

$=3+\frac{3}{17}$

$=\frac{51}{17}+\frac{3}{17}=\frac{54}{17}$

Bài 2:

$a, \frac{4}{5}+\frac{7}{6}·x =\frac{1}{6}$

$\frac{7}{6}·x =\frac{1}{6}-\frac{4}{5}$ 

$\frac{7}{6}·x =\frac{-19}{30}$ 

$x =\frac{-19}{30}:\frac{7}{6}$ 

$x =\frac{-19}{35}$ 

$b, \frac{16}{3}-(x+\frac{1}{2})²=4\frac{1}{3}$ 

$\frac{16}{3}-(x+\frac{1}{2})^{2}=\frac{13}{3}$  

$(x+\frac{1}{2})^{2}=\frac{16}{3}-\frac{13}{3}$  

$(x+\frac{1}{2})²=1$  

$x+\frac{1}{2}=1$  

$x=\frac{1}{2}$ 

$\text{Tham khảo}$

$@Mizameizu$