a,x=4 hoặc -6

b,x=3

Cần lời giải ko bn

a) (x+1) ^2 = 25

    (x+1) ^2 = 5^2

    x  + 1   = 5            Hoặc x + 1 = -5

    x          = 5 - 1                x       = -5 - 1

    x          = 4                     x       = -6

b) 4^5.4^x-1 = 4^7

          4^x-1 = 4^7:4^5

          4^x-1 = 4^7-5

          4^x-1 = 4^2

             x- 1 = 2

              x    = 2+1

              x    = 3

a,\(\left(\dfrac{9}{25}-2.18\right):\left(3\dfrac{4}{5}+0,2\right)\)

\(=\left(\dfrac{9}{25}-36\right):\left(\dfrac{19}{5}+0,2\right)\)

\(=-\dfrac{891}{25}:4\)

\(=-\dfrac{891}{100}\)

b,\(\dfrac{5^4.20^4}{25^5.4^5}\)

\(=\dfrac{5^4.20^4}{\left(5^2\right)^5.\left(2^2\right)^5}\)

\(=\dfrac{5^4.20^4}{5^{10}.2^{10}}\)

\(=\dfrac{20^4}{5^6.2^{10}}\)

A) x + 4 = -16

           x = -16 - 4

           x = -20

Vậy x = -20

b) 12- ( x - 5 ) =5.4

     12 -x -5      = 20 

                  x   = 7 - 20 

                  x   = -13

Vậy x= -13

c) (-2)x - ( x - 17 ) = 34 - ( -x + 25 )

    ( -2 )x - x + 17   = 34 + x - 25

            -3x   + 17   = 11 + x

            -3x - x        = 11 - 17

               -4x          =  -6

                        x    = 1,5

Vậy x = 1,5

d) 17x - ( -16x - 37 ) = 2x + 43 

       17x + 16x - 2x   = 43 -37

          30x                 = 6

                  x             = 0,2

Vậy x = 0,2

\(5,4\times2,8+0,6\times0,8\times9\times4+0,54\times940\)
\(=5,4\times2,8+\left(0,6\times9\right)\times\left(0,8\times4\right)+0,54\times10\times94\)
\(=5,4\times2,8+5,4\times3,2+5,4\times94\)
\(=5,4\times\left(2,8+3,2+94\right)\)
\(=5,4\times100\)
\(=540\)

4^5=2^10

9^4=3^8

2*6^9=2^10*3^9

thì cái tử sẽ đc:

2^10*(-3)

mẫu e phân tích tt

Ta có

\(E=\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\cdot\frac{5^4.20^4}{25^5.4^5}\)

\(=\frac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^{10}.3^8.5}\cdot\frac{2^8.5^8}{5^{10}.2^{10}}\)

\(=\frac{2^{10}.3^8.\left(1-3\right)}{2^{10}.3^8.\left(1+5\right)}\cdot\frac{1}{5^2.2^2}\)

\(=\frac{\left(-2\right)}{6}\cdot\frac{1}{100}=-\frac{1}{3}\cdot\frac{1}{100}=-\frac{1}{300}\)

Vậy : \(E=-\frac{1}{300}\)

Bài làm

\(E=\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}.\frac{5^4.20^4}{25^5.4^5}\)

\(\Rightarrow E=\frac{2^{10}.3^8-2.2^9.3^9}{2^{10}.3^8+2^8.3^8.2^2.5}.\frac{5^4.4^4.5^4}{5^{10}.4^5}\)

\(\Rightarrow E=\frac{2^{10}.3^8-2^{10}.3^9}{2^{10}.3^8+2^{10}.3^8.5}.\frac{5^8.4^4}{5^{10}.4^5}\)

\(\Rightarrow E=\frac{2^{10}\left(3^8-3^9\right)}{2^{10}\left(3^8+3^8.5\right)}.\frac{1}{5^2.4}\)

\(\Rightarrow E=\frac{3^8-3^9}{3^8\left(1+5\right)}.\frac{1}{100}\)

\(\Rightarrow E=\frac{3^8\left(1-3\right)}{3^8\left(1+5\right)}.\frac{1}{100}\)

\(\Rightarrow E=-\frac{2}{6}.\frac{1}{100}\)

\(\Rightarrow E=-\frac{1}{300}\)

a) 123-5.(x-4)=38

=> 5(x-4)=85

=>x-4=85:5=17

=> x=21

tíc mình nha

a ) 123 - 5 . ( x - 4 ) = 38

              5 . ( x - 4 ) = 85

                      x - 4  = 17

                          x  = 21

b ) 2 . x - 183 = 2 ^ 3  . 3  ^ 2

     2 . x - 183 = 72

     2 .  x         = 255

           x         = 127 , 5

c ) 10 + 2 . x = 4 ^ 5 . 4 ^ 3

     10 + 2 .x = 65536

            2 . x = 65526

                x  = 32763

d ) 25 + ( 177 - x ) = 3 ^ 2 . 2 ^ 2

     25 + ( 177 - x ) = 36

                177 - x  = 11

                         x = 166

Cảm ơn Minh Ánh