@Lê Thanh Ngọc bạn đăng câu `x` mà bạn để dưới bình luận lên diễn đàn đi ạ!

Sorry bạn vì kết quả dòng cuối

`=0 ` mới đúng ạ

\(\left[184:\left(96-124:31\right)-2\right].3651\)

\(=\left[184:\left(96-4\right)-2\right].3651\)

\(=\left[184:92-2\right].3651\)

\(=\left[2-2\right].3651\)

\(=0.3651\)

`= 3651`

Câu c mình làm lại ạ:

\(c,\dfrac{7}{13}.\dfrac{5}{19}+\dfrac{7}{19}.\dfrac{8}{13}-3\dfrac{7}{19}\)

\(=\dfrac{7}{19}.\dfrac{5}{13}+\dfrac{7}{19}.\dfrac{8}{13}-3\dfrac{7}{19}\)

\(=\dfrac{7}{19}.\left(\dfrac{5}{13}+\dfrac{8}{13}\right)-3\dfrac{7}{19}\)

\(=\dfrac{7}{19}.1-3\dfrac{7}{19}\)

\(=\dfrac{7}{19}-\dfrac{64}{19}\)

\(=-\dfrac{57}{19}=-3\)

\(a,\dfrac{21}{25}.\dfrac{11}{9}.\dfrac{5}{7}\)

\(=\dfrac{21.11.5}{25.9.7}\)

\(=\dfrac{1.11.1}{5.3.1}\)

\(=\dfrac{11}{15}\)

\(b,\dfrac{5}{23}.\dfrac{17}{26}+\dfrac{5}{23}.\dfrac{9}{26}\)

\(=\dfrac{5}{23}.\left(\dfrac{17}{26}+\dfrac{9}{26}\right)\)

\(=\dfrac{5}{23}.1\)

\(=\dfrac{5}{23}\)

\(c,\dfrac{7}{13}.\dfrac{5}{19}+\dfrac{7}{19}.\dfrac{8}{13}\)

\(=\dfrac{7}{19}.\dfrac{5}{13}+\dfrac{7}{19}.\dfrac{8}{13}\)

\(=\dfrac{7}{19}.\left(\dfrac{5}{13}+\dfrac{8}{13}\right)\)

\(=\dfrac{7}{19}.1\)

\(=\dfrac{7}{19}\)

\(119\times24-53\times23-24\times66\)

\(=\left(119-66\right)\times24-53\times23\)

\(=53\times24-53\times23\)

\(=53\times\left(24-23\right)\)

\(=53\times1\)

\(=53\)

\(3^{x+2}-5.3^x=36\)

\(3^x.9-5.3^x=36\)
\(3^x.\left(9-5\right)=36\)

\(3^x.4=36\)

\(3^x=36:4\)

\(3^x=9\)

\(3^x=3^2\)

\(\Rightarrow x=2\)

Vậy \(x=2\)

\(a,14364:9+20020\)

\(=1596+20020\)

\(=21616\)

\(b,\left(10356\times5-780\right):6\)

\(=\left(51780-780\right):6\)

\(=51000:6\)

\(=8500\)

`c`

\(=51000:6\)

Vậy `9276 : 39 = 237`(dư`33`)

\(\left(-2\right)+\left(-4\right)\)

\(=-\left(2+4\right)\)

\(=-6\)

\(1-2.\left(3-2\right)\)

\(=1-2.1\)

\(=1-2\)

\(=1+\left(-2\right)\)

\(=-1\)