a) \(\dfrac{11\cdot8-11\cdot3}{17-6}\)

\(=\dfrac{11\cdot\left(8-3\right)}{11}=5\)

b) \(\dfrac{24-12\cdot13}{12+4\cdot9}\)

\(=\dfrac{12\cdot\left(2-13\right)}{12\left(1+3\right)}=\dfrac{-11}{4}\)

\(\frac{3.7.8.13}{14\cdot15\cdot26}=\frac{3\cdot7\cdot8\cdot13}{2\cdot7\cdot3\cdot5\cdot2\cdot13}=\frac{8}{5\cdot2\cdot2}=\frac{8}{20}=\frac{2}{5}\)

\(\frac{3.7.8.13}{14.15.26}=\frac{3.7.2^3.13}{2.7.3.5.13.2}=\frac{1.7.2.1}{1.1.1.5.1.1}=\frac{14}{5}\)

\(\frac{11.8-11.3}{17-6}=\frac{11.\left(8-3\right)}{11}=\frac{11.5}{11}=\frac{1.5}{1}=\frac{5}{1}=5\)

\(\frac{-17.13+17.2}{11.2-11.9}=\frac{-17.13+\left(-17\right).2}{11.\left(2-9\right)}=\frac{-17.\left(-13+2\right)}{11.\left(-7\right)}=\frac{-17.\left(-11\right)}{11.\left(-7\right)}=\frac{-17.\left(-1\right)}{-1.\left(-7\right)}=\frac{17}{7}\)

\(\frac{7}{9.10^2-2.10^2}=\frac{7}{100\left(9-2\right)}=\frac{7}{100.7}=\frac{7}{700}=\frac{1}{100}\)

mình làm được tới đó thôi, hihi. 

Co ai biết lam con thu 5 ko, giúp minh voi. Dang mai minh nộp bai roi

27/-72 = 27:(-9)/-72:(-9) = -3/8

-2020:(-2020)/-4040:(-2020) = 1/2

11.8-11.3/17-6= 11.(8-3)/11= 11.5/11= 5

20-12.30/30+30.10 = 20-360/30+300 = -340/330 = -34/33 = -1 1/33

\(\text{#TuanNam}\)

`27/-72=-27/72=`\(\dfrac{-27\div9}{72\div9}=\dfrac{-3}{8}\) 

`-2020/-4040=202/404=`\(\dfrac{202\div202}{404\div202}=\dfrac{1}{2}\)

`11*8-`\(\dfrac{11\cdot3}{17-6}=88-3=85\) 

\(\dfrac{20-12\cdot20}{30+30\cdot10}=\dfrac{20\cdot\left(1-12\right)}{30\cdot\left(1+10\right)}=\dfrac{20\cdot-11}{30\cdot11}=-\dfrac{2}{3}\) 

giúp em với 

\(=\dfrac{11\cdot\left(-5\right)}{11}=-5\)

RÚT GỌN VỀ PHÂN SỐ TỐI GIẢN

câu a) \(\dfrac{-147}{252}=\dfrac{-7}{12}\)

câu b) \(\dfrac{765}{900}=\dfrac{17}{20}\)

câu c) \(\dfrac{11\cdot3-11\cdot8}{17-6}=\dfrac{-5}{1}\)

câu d) \(\dfrac{3^5\times2^4}{8\times3^6}=\dfrac{2}{3}\)

câu e) \(\dfrac{84\cdot45}{49\cdot54}=\dfrac{10}{7}\)

a) 5

b)  − 11 4

c)  2 3

d)  1 100

e) 5

f) 1

Bài 14 : 

a. 55/66 = 55 : 11/66 : 11 = 5/6          b. -33/88 = -33 : 11/88 : 11 = -3/8        c. 2020/8080 = 2020 : 2020/8080 : 2020 = 1/4      

d. 2121/-4242 = 2121 : (-101)/(-4242) : (-101) = 21/42 = 1/2     

e. 130130/-260260 = 130130 : (-1001)/(-260260) : ( -1001 ) = -130/260 = -1/2

f. 1616/-1313 = 1616 : (-101)/(-1313) : (-101 ) = -16/13

 Chúc bạn học tốt nha !

Bài 14 khá đơn giản nên mình sẽ bỏ qua, bạn tự làm đc mà xD

15. a) \(\frac{13\cdot9-13\cdot2}{25-12}=\frac{13\left(9-2\right)̸}{13}=7\)

b) \(\frac{42-14\cdot8}{7+21\cdot3}=\frac{14\cdot3-14\cdot8}{7+63}=\frac{14\left(3-8\right)}{70}=\frac{14\cdot\left(-5\right)}{70}=\frac{-70}{70}=-1\)

c) \(\frac{9\cdot6-18\cdot4}{12\cdot3}=\frac{\left(9\cdot2\right)\cdot\left(6:2\right)-18\cdot4}{36}=\frac{18\cdot3-18\cdot4}{36}=\frac{18\left(3-4\right)}{36}=\frac{-18}{36}=\frac{-1}{2}\)

d) \(\frac{5\cdot5^2}{9\cdot10^2-4\cdot10^2}=\frac{5\cdot5^2}{10^2\left(9-4\right)}=\frac{5\cdot5^2}{10^2\cdot5}=\frac{1}{2^2}=\frac{1}{4}\)

e) \(\frac{\left(-7\right)\cdot3-4\cdot\left(-6\right)}{\left(-5\right)\cdot3-2\cdot3}=\frac{-21+24}{-15-6}=\frac{3}{-21}=\frac{-1}{7}\)

f) \(\frac{\left(-17\right)\cdot13+17\cdot2}{-11\cdot2-11\cdot19}=\frac{-\left[17\cdot\left(13+2\right)\right]}{-\left[11\cdot\left(2-19\right)\right]}=\frac{-17\cdot13-\left(-17\right)\cdot2}{-11\cdot2+\left(-11\right)\cdot19}=\frac{-17\left(13-2\right)}{-11\left(2+19\right)}=\frac{-17\cdot11}{-11\cdot19}=\frac{-17}{-19}=\frac{17}{19}\)

* Hơi dài xD , mong bạn thông cảm *

a: \(=\dfrac{-4\cdot13\cdot9\cdot5}{3\cdot4\cdot5\cdot2\cdot13}=\dfrac{3}{2}\)

b: \(=\dfrac{1}{2}\cdot\dfrac{1}{3}\cdot5=\dfrac{5}{6}\)