3.4x-2+4x-1+4x=92

4x(3+1+1)-2-1=92

4x.5-2-1=92

4x.5 =92+1+2

4x.5 =95

4x  =95:5

4x   =19 

3.4x-2+4x-1+4x=92

4x(3+1+1)-2-1=92

4x.5-2-1=92

4x.5 =92+1+2

4x.5 =95

4x  =95:5

4x   =19 

đây em nhé

\(3\cdot4^{x-2}+4^{x-1}+4^x=92\)

\(4^{x-2}\left(3+4+4^2\right)=92\)

\(4^{x-2}\cdot23=92\)

\(4^{x-2}=4\)

\(x-2=1\)

\(x=3\)

\(=12-32\cdot\left\{800:407\right\}=12-32\cdot\dfrac{800}{407}=\dfrac{-20716}{407}\)

A(x) ở đâu

Đề có gì đó hơi sai sai 

a) Ta có: A(x)=M(x)-N(x)

\(=\dfrac{5}{2}x^2-\dfrac{1}{2}x-x^3-1-\left(-2x^3+5x^2-12+4x\right)\)

\(=\dfrac{5}{2}x^2-\dfrac{1}{2}x-x^3-1+2x^3-5x^2+12-4x\)

\(=x^3-\dfrac{5}{2}x^2-\dfrac{9}{2}x+11\)

\(\dfrac{1}{5}\times x-\dfrac{2}{3}=\dfrac{1}{10}\times x+\dfrac{5}{6}\)

\(\dfrac{1}{5}x-\dfrac{2}{3}-\dfrac{1}{10}x-\dfrac{5}{6}=0\)

\(\dfrac{1}{5}x-\dfrac{1}{10}x-\dfrac{2}{3}-\dfrac{5}{6}=0\)

\(\dfrac{1}{10}x-\dfrac{3}{2}=0\)

\(\dfrac{1}{10}x=\dfrac{3}{2}\)

\(x=15\)

           \(\dfrac{1}{5}\).x - \(\dfrac{2}{3}\) = \(\dfrac{1}{10}\).x + \(\dfrac{5}{6}\)

⇒   \(\dfrac{1}{5}\).x - \(\dfrac{1}{10}\).x = \(\dfrac{5}{6}\) + \(\dfrac{2}{3}\)

⇒ \(\dfrac{2}{10}\).x - \(\dfrac{1}{10}\).x = \(\dfrac{5}{6}\) + \(\dfrac{4}{6}\)

⇒            \(\dfrac{1}{10}\).x = \(\dfrac{9}{6}\)

⇒                  x = \(\dfrac{9}{6}\) : \(\dfrac{1}{10}\)

⇒                  x = \(\dfrac{9}{6}\) . 10

⇒                  x = \(\dfrac{90}{6}\)

⇒                  x = 15

       Vậy x = 15

\(1)\)\(-\dfrac{10}{11}.\dfrac{8}{9}+\dfrac{7}{18}.\dfrac{10}{11}\)

\(=\dfrac{10}{11}\left(-\dfrac{8}{9}+\dfrac{7}{18}\right)\)

\(=\dfrac{10}{11}\left(\dfrac{-16}{18}+\dfrac{7}{18}\right)\)

\(=\dfrac{10}{11}.\left(-\dfrac{1}{2}\right)=-\dfrac{5}{11}\)

\(2)\)\(\dfrac{12}{25}.\dfrac{23}{7}-\dfrac{12}{7}.\dfrac{13}{25}\)

\(=\dfrac{12}{7}.\dfrac{23}{25}-\dfrac{12}{7}.\dfrac{13}{25}\)

\(=\dfrac{12}{7}.\left(\dfrac{23}{25}-\dfrac{13}{25}\right)\)

\(=\dfrac{12}{7}.\dfrac{2}{5}=\dfrac{24}{35}\)

\(3)\)\(\dfrac{3}{7}.\dfrac{16}{15}-\dfrac{2}{15}.\dfrac{-3}{7}\)

\(=\dfrac{3}{7}.\dfrac{16}{15}-\dfrac{3}{7}.\dfrac{-2}{15}\)

\(=\dfrac{3}{7}.\left(\dfrac{16}{15}+\dfrac{2}{15}\right)\)

\(=\dfrac{3}{7}.\dfrac{18}{15}=\dfrac{18}{35}\)

\(4)\)\(-\dfrac{4}{13}.\dfrac{5}{17}+\dfrac{-12}{13}.\dfrac{4}{17}\)

\(=-\dfrac{4}{13}.\dfrac{5}{17}+\dfrac{-4}{13}.\dfrac{12}{17}\)

\(=-\dfrac{4}{13}.\left(\dfrac{5}{17}+\dfrac{12}{17}\right)\)

\(=-\dfrac{4}{13}.\dfrac{17}{17}=-\dfrac{4}{13}\)

`#040911`

`1)`

`-10/11 * 8/9 + 7/18 . 10/11`

`= 10/11 * (-8/9 + 7/18)`

`= 10/11 * (-1/2)`

`= -5/11`

`2)`

`12/25 * 23/7 - 12/7 *13/25`

`= 12/7 * 23/25 - 12/7 * 13/25`

`= 12/7 * (23/25 - 13/25)`

`= 12/7 * 2/5`

`= 24/35`

`3)`

`3/7 * 16/15 - 2/15 * (-3)/7`

`= 3/7 * (16/15 + 2/15)`

`= 3/7 * 6/5`

`= 18/35`

`4)`

`-4/13 * 5/17 + (-12)/13 * 4/17`

`= -4/17 * 5/13 + (-12)/13 * 4/17`

`= 4/17 * (-5/13 - 12/13)`

`= 4/17 * (-17)/13`

`= -4/13`

Ta có:\(\left(4x+28\right)⋮\left(2x+1\right)\Rightarrow\left[\left(4x+2\right)+26\right]⋮\left[2\left(2x+1\right)\right]\)

           \(\Rightarrow\left[\left(4x+2\right)+26\right]⋮\left(4x+2\right)\)

            \(\Rightarrow26⋮\left(4x+2\right)\)(t/c chia hết của 1 tổng)

         Vì \(x\in N\Rightarrow4x+2\in N\)(1)

           \(\Rightarrow\left(4x+2\right)\in\left\{2;13;26\right\}\)

             \(\Rightarrow x\in\left\{0;\frac{11}{4};6\right\}\)

   Từ (1)=>\(x\in\left\{0;6\right\}\)

                 Có gì ko hiểu thì kbạn với mình nha

a) \(\dfrac{1}{3}+\dfrac{3}{5}+\dfrac{1}{15}-\dfrac{3}{4}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{72}\)

\(=\dfrac{5+9+1}{15}-\dfrac{27+8+1}{36}+\dfrac{1}{72}=1-1+\dfrac{1}{72}=\dfrac{1}{72}\)

b) \(=\dfrac{1}{5}-\dfrac{1}{5}-\dfrac{3}{7}+\dfrac{3}{7}+\dfrac{5}{9}-\dfrac{5}{9}-\dfrac{1}{11}+\dfrac{1}{11}+\dfrac{7}{13}-\dfrac{7}{13}-\dfrac{9}{16}\)

\(=\dfrac{9}{16}\)

18 - 4\(x\) = -20 - 6\(x\) 

-4\(x\) + 6\(x\) = - 20  - 18

      2\(x\)    = - 38

         \(x\)  = - 19

h, -15 \(\times\) 24 = -7\(x\) + 32

     7\(x\) = 360 + 32

      7\(x\) = 392

         \(x\) =  392:7

          \(x\) = 56

i, 15\(x\) -3.(4\(x\) - 6) = -12 + 36

    15\(x\) - 12\(x\) + 18 =  24

      3\(x\) = 24 - 18

       3\(x\) = 6

         \(x\) = 2

k, -10\(x\) - 27 = -7\(x\) + 33

    -27 - 33 = -7\(x\) + 10\(x\)

     3\(x\) = -60

        \(x\) = -20

m, -17\(x\) - 24 = - 9\(x\) - 40

     - 24 + 40 =  -9\(x\) + 17\(x\)

          8\(x\) = 16

             \(x\) = 2

n, -23 \(\times\) 25 = -18\(x\) + 75

     -575 = -18\(x\) + 75

       18\(x\) = 575 + 75

        18\(x\) = 650

              \(x\) = \(\dfrac{325}{9}\)

i mean 2009 lol

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