Mk sửa đề nha :

\(C=\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+\frac{12}{7}\)

   \(=\frac{-5}{7}.\left(\frac{2}{11}+\frac{9}{11}\right)+\frac{12}{7}\)

   \(=\frac{-5}{7}.1+\frac{12}{7}\)

   \(=\frac{-5}{7}+\frac{12}{7}\)

   \(=1\)

Study well ! >_<

A= \(\frac{19}{23}\)

\(\frac{19}{23}\)

\(\frac{8}{3}\cdot\frac{2}{5}\cdot\frac{3}{8}\cdot10\cdot\frac{19}{92}=\left(\frac{8}{3}\cdot\frac{3}{8}\right)\cdot\left(\frac{2}{5}\cdot10\right)\cdot\frac{19}{92}=1\cdot4\cdot\frac{19}{92}=4\cdot\frac{19}{92}=\frac{19}{23}\)

\(\frac{8}{3}.\frac{2}{5}.\frac{3}{8}.10.\frac{19}{92}\)

\(=(\frac{8}{3}.\frac{3}{8}).(\frac{2}{5}.10).\frac{19}{92}\)

\(=4.\frac{19}{92}\)

\(=\frac{19}{23}\)

Hok tôt !!!!!!!!!!!!!!!

\(\frac{8}{3}\times\frac{2}{5}\times\frac{3}{8}\times10\times\frac{19}{92}=\frac{8\times2\times3\times10\times19}{3\times5\times8\times92}=\frac{2\times19}{46}=\frac{2\times19}{2\times23}=\frac{19}{23}\)

làm ơn chọn mk để mk lên 700 điểm hỏi đáp với

=8/3.2/5.3/8.10.19/92

=16/15.3/8.10.19/92

=2/5.10.19/92

=19/23

1; 5.2² + (\(x\) + 3) = 5²

   5.4  +  (\(x\) + 3) = 25

    20 + (\(x\) + 3) = 25

             \(x\) + 3 = 25 - 20

             \(x+3\) = 5

             \(x\)       = 5  - 3

            \(x\)        = 2

            Vậy \(x=2\)

2; 2³ + (\(x\) - 3²) = 5³ - 4³

   8 +  (\(x\) - 9)    = 125 - 64

   8 + (\(x\) - 9) = 61

         \(x\) - 9 = 61 - 8

         \(x\) - 9 = 53

        \(x\)        = 53  + 9

        \(x\)       = 62

        Vậy \(x\) = 62

3; 3.2 + (\(x\) + 5²) = 10²

       6 + (\(x\) + 25) = 100

              \(x\) + 25 = 100 - 6

              \(x\) + 25  = 94

               \(x\)          = 94 - 25

               \(x\)          = 69

Vậy \(x\) = 69