Đây nữa .Cảm ơn các bạn nhiều .

m. 31/23-(7/32+8/23)

n. (1/3+12/67+13/41)-(79/67-28/41)

o. 38/45-(8/45-17/51-3/11)

a)

\(\dfrac{6}{13}\cdot\dfrac{8}{7}\cdot\dfrac{-26}{3}\cdot\dfrac{-7}{8}\)

\(=\dfrac{6}{13}\cdot\dfrac{-26}{3}\cdot\dfrac{8}{7}\cdot\dfrac{-7}{8}\)

\(=-4\cdot\left(-1\right)\\ =4\)

b)

\(\dfrac{6}{11}+\dfrac{11}{3}\cdot\dfrac{3}{22}\)

\(=\dfrac{6}{11}+\dfrac{1}{2}\\ =\dfrac{12}{22}+\dfrac{11}{22}\\ =\dfrac{23}{22}\)

a)=  (6/13*-26/3)* (8/7*-7/8)

= -4*-1=4

b=6/11+1/2=(12+11)/22=23/22

a. \(\dfrac{6.8.\left(-26\right).\left(-7\right)}{13.7.3.8}=\dfrac{2.3.8.\left(-13\right).2.\left(-7\right)}{13.7.3.8}=\dfrac{4}{1}=4\)

\(b.\dfrac{6}{11}+\dfrac{11.3}{3.11.2}\)

\(=\dfrac{6}{11}+\dfrac{1}{2}=\dfrac{23}{22}\)

Ta có : x - (-3/11) = 6/22 +1/4 

x - (-3/11) = 3/11 +1/4 

x - 1/4 = (-3/11) + 3/11 

x-1/4 = 0 

=> x = 1/4 .

-5

\(\left(\dfrac{113+61}{13}\right)-\left(\dfrac{312+22}{13}\right)=\dfrac{174}{13}-\dfrac{334}{13}=\dfrac{-160}{13}\)

-160/13

\(A=\dfrac{5}{11}.\dfrac{5}{7}+\dfrac{5}{11}.\dfrac{2}{7}+\dfrac{6}{11}=\dfrac{5}{11}\left(\dfrac{5}{7}+\dfrac{2}{7}\right)+\dfrac{6}{11}=\dfrac{5}{11}.1+\dfrac{6}{11}=\dfrac{5}{11}+\dfrac{6}{11}=\dfrac{11}{11}=1\)

\(B=\dfrac{3}{13}.\dfrac{6}{11}+\dfrac{3}{13}.\dfrac{9}{11}-\dfrac{3}{13}.\dfrac{4}{11}=\dfrac{3}{13}\left(\dfrac{6}{11}+\dfrac{9}{11}-\dfrac{4}{11}\right)=\dfrac{3}{13}.1=\dfrac{3}{13}\)

\(C=\left(\dfrac{12}{16}-\dfrac{31}{22}+\dfrac{14}{91}\right)\left(\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{1}{6}\right)=\left(\dfrac{12}{16}-\dfrac{31}{22}+\dfrac{14}{91}\right)\left(\dfrac{3}{6}-\dfrac{2}{6}-\dfrac{1}{6}\right)=\left(\dfrac{12}{16}-\dfrac{31}{22}+\dfrac{14}{91}\right).0=0\)

\(\dfrac{5}{6}:4=\dfrac{5}{6}x\dfrac{1}{4}=\dfrac{5}{24}\)

\(\dfrac{10}{11}-\dfrac{3}{22}=\dfrac{20}{22}-\dfrac{3}{22}=\dfrac{17}{22}\)

5/6:4=5/6.1/4=5/24

10/11-3/22=20/22-3/22=17/22