X+X+1/2x2/5+X+8/10=136

3X+1/5+4/5=136

3X+1=136

3X    =136-1=135

   X    =135:3=45

X+X+\(\frac{1}{2}x\frac{2}{5}\)+X+\(\frac{8}{10}\)=136

X.(1+1+1)+\(\frac{1}{5}+\frac{8}{10}\)=136

3X+1=136

3X     =136-1

3X    =135

X      =135:3

X      =45

Vậy X=45

Chúc bn học tốt

a ) \(x+x+x+\frac{1}{2}\times\frac{2}{5}+x+\frac{1}{10}+x=136\)

                                                                \(5x+1=136\)

                                                                         \(5x=135\)

                                                                             \(x=27\)

b ) \(3\frac{1}{2}-x:\frac{3}{5}=\frac{3}{2}\)

                   \(x:\frac{3}{5}=2\)

                         \(x=\frac{6}{5}\)

1: 7-x=8+(-7)

=>7-x=8-7=1

=>x=7-1=6

2: \(x-8=\left(-3\right)-8\)

=>x-8=-11

=>\(x=-11+8=-3\)

3: \(2-x=10-9+23\)

=>\(2-x=33-9=24\)

=>x=2-24=-22

4: \(-2-x=15\)

=>\(x=-2-15=-17\)

5: \(-7+x-8=-3-1+13\)

=>x-14=13-4=9

=>x=9+14=23

6: 100-x+7=-x+3

=>107-x=3-x

=>107=3(vô lý)

7: \(23+x=8-2x\)

=>\(x+2x=8-23\)

=>3x=-15

=>x=-15/3=-5

`#3107`

b)

`2.3^x = 162`

`\Rightarrow 3^x = 162 \div 2`

`\Rightarrow 3^x = 81`

`\Rightarrow 3^x = 3^4`

`\Rightarrow x = 4`

Vậy, `x = 4`

c)

`(2x - 15)^5 = (2 - 15)^3`

\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`

\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`

\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)

`d)`

\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!

`e)`

\(7\cdot4^{x-1}+4^{x-1}=23?\)

\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)

Bạn xem lại đề!

`f)`

\(2\cdot2^{2x}+4^3\cdot4^x=1056\)

\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy, `x = 2`

_____

\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)

\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)

\(\Rightarrow\left(x\div3+17\right)\div10=2\)

\(\Rightarrow x\div3+17=20\)

\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)

Vậy, `x = 9.`

`136 -4^2 : x=134`

`=> 136-16:x=134`

`=> 16:x= 136-134`

`=> 16:x=2`

`=>x=16:2`

`=>x=8`

__

`19-5(x-1)=4`

`=> 5(x-1)=19-4`

`=> 5(x-1) =15`

`=> x-1=15:5`

`=>x-1=3`

`=>x=3+1`

`=>x=4`

__

`257-(x^2-1) =177`

`=>x^2-1=257-177`

`=>x^2-1=80`

`=>x^2=80+1`

`=>x^2=81`

`=>x^2=(+- 9)^2`

`=> x= +- 9`

__

`(x^2-17) : 8=2^3`

`=> x^2 -17 = 8 * 8`

`=> x^2 -17= 64`

`=> x^2 =64+17`

`=>x^2=81`

`=>x^2=(+- 9)^2`

`=> x= +- 9`

136 - 4² : x = 134

4² : x = 136 - 134

8 : x = 2

x = 8 : 2

x = 4

--------

129 - 5(x - 1) = 4

5(x - 1) = 129 - 4

5(x - 1) = 125

x - 1 = 125 : 5

x - 1 = 25

x = 25 + 1

x = 26

------------

257 - (x² - 1) = 177

x² - 1 = 257 - 177

x² - 1 = 80

x² = 80 + 1

x² = 81

x = -9 hoặc x = 9

--------

(x² - 17) : 8 = 8

x² - 17 = 8 . 8

x² - 17 = 64

x² = 64 + 17

x² = 81

x = -9 hoặc x = 9