a) Ta có: BCNN(15,10) = 30 nên ta chọn mẫu số chung là 30

\(\frac{11}{15}+\frac{9}{10}=\frac{22}{30}+\frac{27}{30}=\frac{49}{30}\)

b) Ta có: BCNN(6,9,12) = 36 nên ta chọn mẫu số chung là 36

\(\frac{5}{6} + \frac{7}{9} + \frac{{11}}{{12}} = \frac{{30}}{{36}} + \frac{{28}}{{36}} + \frac{{33}}{{36}} = \frac{{91}}{{36}}\)

c) Ta có: BCNN(24,21) = 168 nên ta chọn mẫu số chung là 168

\(\frac{7}{{24}} - \frac{2}{{21}} = \frac{{49}}{{168}} - \frac{{16}}{{168}} = \frac{{33}}{{168}}=\frac{11}{56}\)

d) Ta có: BCNN(36,24) = 72 nên ta chọn mẫu số chung là 72

\(\frac{{11}}{{36}} - \frac{7}{{24}} = \frac{{22}}{{72}} - \frac{{21}}{{72}} = \frac{1}{{72}}\)

-7/24 nhé giúp

\(\dfrac{11}{36}-\dfrac{-7}{24}=\dfrac{22}{72}-\dfrac{-21}{72}=\dfrac{43}{72}\)

\(\dfrac{11}{36}-\dfrac{-7}{24}\)

\(=\dfrac{11}{36}+\dfrac{7}{24}\)

\(=\dfrac{264}{864}+\dfrac{252}{864}\)

\(=\dfrac{516}{864}\)

\(\left(\frac{7}{36}-\frac{\frac{5}{48+11}}{24}\right)\cdot4\)

\(=\left(\frac{7}{36}-\frac{5}{59}:24\right)\cdot4\)

\(=\left(\frac{7}{36}-\frac{5}{59}\cdot\frac{1}{24}\right)\cdot4\)

\(=\left(\frac{7}{36}-\frac{5}{1416}\right)\cdot4=\frac{811}{4248}\cdot4=\frac{811}{1062}\)

Đề bài như thế này hay sao vậy? Mỗi khi bạn biểu tính phân số thì bạn gõ latex cho nó dễ

`11/36-(-7/24)`

`=11/36+7/24`

`=22/72+21/72`

`=43/72`

\(\dfrac{11}{36}-\dfrac{-7}{24}=\dfrac{22}{72}-\dfrac{-21}{72}=\dfrac{22-\left(-21\right)}{72}=\dfrac{43}{72}\)

-11/12-(-1) = 1/12

-1/6-1/15 = -7/30

11/36-(-7)/24 = 43/72

a) (25x32) : 8           

= 25 x (4 x 8) : 8

= (25 x 4) x (8:8)

= 100 x 1

=100

b, 24 x 11 + 6 x 86 x 4 + 72

= 24 x 11 + (6 x 4) x 86 + 24 x 3

= 24 x 11 + 24 x 86 + 24 x 3

= 24 x (11+86+3)

= 24 x 100

= 2 400

\(\left(25\times32\right):8=25\times32:8=25\times\left(32:8\right)=25\times4=100\\ 24\times11+6\times86\times4+72\\ =24\times11+24\times86+24\times3\\ =24\times\left(11+86+3\right)\\ =24\times100=2400\\ 36\times5+9\times79\times4+72\times8\\ =36\times5+36\times79+36\times16\\ =36\times\left(5+79+16\right)\\ =36\times100=3600\\ \left(56\times125\right):7=56\times125:7=\left(56:7\right)\times125=8\times125=1000\)

a: \(=\dfrac{-5}{8}+\dfrac{7}{12}=\dfrac{-15}{24}+\dfrac{14}{24}=\dfrac{-1}{24}\)

b: \(=\dfrac{3}{4}-\dfrac{5}{6}+\dfrac{11}{12}=\dfrac{9}{12}-\dfrac{10}{12}+\dfrac{11}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)

c: \(=\dfrac{6}{36}-\dfrac{1}{36}=\dfrac{5}{36}\)

d: \(=\dfrac{5}{12}+\dfrac{5}{12}=\dfrac{10}{12}=\dfrac{5}{6}\)

e: \(=\dfrac{-8}{56}-\dfrac{7}{56}=\dfrac{-15}{56}\)

f: \(=\dfrac{-5}{15}+\dfrac{3}{25}=\dfrac{-25}{75}+\dfrac{9}{75}=\dfrac{-16}{75}\)

Tính nhanh:

  \(\frac{11}{24}-\frac{5}{41}\)\(+\frac{13}{24}+0,5-\)\(\frac{36}{41}\)

\(=\left(\frac{11}{24}+\frac{13}{24}\right)\)\(-\left(\frac{5}{41}+\frac{36}{41}\right)\)\(+0,5\)

\(=1-1+0,5\)

\(=0,5\)

\(\frac{11}{24}-\frac{5}{41}+\frac{13}{24}+0,5-\frac{36}{41}\)

\(=\left(\frac{11}{24}+\frac{13}{24}\right)-\left(\frac{5}{41}+\frac{36}{41}\right)+0,5\)

\(=1-1+0,5\)
\(=0+0,5\)
\(=0,5\)
Chúc bạn học tốt.

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\(\frac{11}{24}-\frac{5}{41}+\frac{13}{24}+0,5-\frac{36}{41}\)

\(=\)\(\left(\frac{11}{24}+\frac{13}{24}\right)-\left(\frac{5}{41}+\frac{36}{41}\right)+0,5\)

\(=\)\(1-1+0,5\)

\(=\)\(0+0,5\)

\(=\)\(0,5\)