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18 tháng 9 2021

\(5^x+5^{x+2}+5^{x+4}=3255\)

\(\Rightarrow5^x\left(1+5^2+5^4\right)=3255\)

\(\Rightarrow5^x.651=3255\)

\(\Rightarrow5^x=5\Rightarrow x=1\)

18 tháng 9 2021

\(5^x+5^{x+2}+5^{x+4}=3255\)

\(5^x+5^x.5^2+5^x.5^4=3255\)

\(5^x.\left(5^2+5^4+1\right)=3255\)

\(5^x.651=3255\)

\(5^x=3255:651\)

\(5^x=5\)

\(\Rightarrow x=1\)

1: =>25x-15-6x+12=11-5x

=>19x-3=11-5x

=>24x=14

=>x=7/12

2: =>8-12x-5+10x=4-6x

=>4-6x=-2x+3

=>-4x=-1

=>x=1/4

9 tháng 6 2019

\(|x^2-5x+4|=4x-4\)

\(\Rightarrow|\left(x-1\right)\left(x-4\right)|=4\left(x-1\right)\)

\(\Rightarrow\orbr{\begin{cases}\left(x-1\right)\left(x-4\right)=4\left(x-1\right)\\\left(x-1\right)\left(x-4\right)=-4\left(x-1\right)\end{cases}}\)

TH1 :

\(\left(x-1\right)\left(x-4\right)=4\left(x-1\right)\)

\(\Rightarrow\left(x-1\right)\left(x-4\right)-4\left(x-1\right)=0\)

\(\Rightarrow\left(x-1\right)\left(x-8\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x=1\\x=8\end{cases}}\)

Th2: 

\(\left(x-1\right)\left(x-4\right)=-4\left(x-1\right)\)

\(\Rightarrow\left(x-1\right)\left(x-4\right)+4\left(x-1\right)=0\)

\(\Rightarrow\left(x-1\right)x=0\)

\(\Rightarrow\orbr{\begin{cases}x=1\\x=0\end{cases}}\)

\(\Rightarrow S=\left\{0;1;8\right\}\)

17 tháng 9 2018

\(\frac{4+5x}{-2}=\frac{4}{\left(5x+4\right)^2}\)

\(\frac{5x+4}{-2}=\frac{4}{\left(5x+4\right)^2}\)

\(\Leftrightarrow\left(5x+4\right)^2\cdot\left(5x+4\right)=4\cdot\left(-2\right)\)

\(\Leftrightarrow\left(5x+4\right)^3=-8=\left(-2\right)^3\)

\(\Leftrightarrow5x+4=-2\)

\(\Leftrightarrow5x=-6\)

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

`@` `\text {Ans}`

`\downarrow`

`1)`

\(2x+\dfrac{1}{2}=\dfrac{5}{3}\)

`\Rightarrow`\(2x=\dfrac{5}{3}-\dfrac{1}{2}\)

`\Rightarrow`\(2x=\dfrac{7}{6}\)

`\Rightarrow`\(x=\dfrac{7}{6}\div2\)

`\Rightarrow`\(x=\dfrac{7}{12}\)

Vậy, `x = 7/12`

`2)`

\(\dfrac{1}{7}+\dfrac{4}{5}x=\dfrac{5}{3}\)

`\Rightarrow`\(\dfrac{4}{5}x=\dfrac{5}{3}-\dfrac{1}{7}\)

`\Rightarrow`\(\dfrac{4}{5}x=\dfrac{32}{21}\)

`\Rightarrow`\(x=\dfrac{32}{21}\div\dfrac{4}{5}\)

`\Rightarrow`\(x=\dfrac{40}{21}\)

Vậy, `x = 40/21`

`3)`

\(\dfrac{3}{5}-\dfrac{3}{5}x=\dfrac{1}{7}\)

`\Rightarrow`\(\dfrac{3}{5}x=\dfrac{3}{5}-\dfrac{1}{7}\)

`\Rightarrow`\(\dfrac{3}{5}x=\dfrac{16}{35}\)

`\Rightarrow`\(x=\dfrac{16}{35}\div\dfrac{3}{5}\)

`\Rightarrow`\(x=\dfrac{16}{21}\)

Vậy, `x = 16/21`

`4)`

\(\dfrac{5}{6}-3x=\dfrac{3}{4}\)

`\Rightarrow`\(3x=\dfrac{5}{6}-\dfrac{3}{4}\)

`\Rightarrow`\(3x=\dfrac{1}{12}\)

`\Rightarrow`\(x=\dfrac{1}{12}\div3\)

`\Rightarrow`\(x=\dfrac{1}{36}\)

Vậy, `x  = 1/36`

`5)`

\(\dfrac{5}{3}-\dfrac{1}{2}x=\dfrac{3}{7}\)

`\Rightarrow`\(\dfrac{1}{2}x=\dfrac{5}{3}-\dfrac{3}{7}\)

`\Rightarrow`\(\dfrac{1}{2}x=\dfrac{26}{21}\)

`\Rightarrow`\(x=\dfrac{26}{21}\div\dfrac{1}{2}\)

`\Rightarrow`\(x=\dfrac{52}{21}\)

Vậy, `x = 52/21`

`6)`

\(5x+\dfrac{1}{2}=\dfrac{2}{3}\)

`\Rightarrow`\(5x=\dfrac{2}{3}-\dfrac{1}{2}\)

`\Rightarrow`\(5x=\dfrac{1}{6}\)

`\Rightarrow`\(x=\dfrac{1}{6}\div5\)

`\Rightarrow`\(x=\dfrac{1}{30}\)

Vậy, `x = 1/30.`

AH
Akai Haruma
Giáo viên
14 tháng 11 2023

Lời giải:

1. $(x+2)-2=0$

$x+2=2$

$x=0$

2.

$(x+3)+1=7$

$x+3=7-1=6$

$x=6-3=3$

3.

$(3x-4)+4=12$

$3x-4+4=12$

$3x=12$

$x=12:3=4$

4.

$(5x+4)-1=13$

$5x+4=13+1=14$

$5x=14-4=10$

$x=10:5=2$

5.

$(4x-8)-3=5$

$4x-8=5+3=8$

$4x=8+8=16$

$x=16:4=4$

6.

$3+(x-5)=7$

$x-5=7-3=4$

$x=4+5=9$

7.

$8-(2x-4)=2$

$2x-4=8-2=6$

$2x=6+4=10$

$x=10:2=5$

8.

$7+(5x+2)=14$

$5x+2=14-7=7$

$5x=7-2=5$

$x=5:5=1$

9.

$5-(3x-11)=1$

$3x-11=5-1=4$

$3x=11+4=15$

$x=15:3=5$

10.

$16-(8x+2)=6$

$8x+2=16-6=10$

$8x=10-2=8$

$x=8:8=1$

25 tháng 2 2020

a)\(|4+5x|+5x=-4\)
\(|4+5x|=-4-5x\)
\(\Rightarrow\left[{}\begin{matrix}4+5x=-4-5x\\4+5x=-\left(-4-5x\right)\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}5x+5x=-4-4\\4+5x=4+5x\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}10x=-8\\5x-5x=4-4\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\frac{8}{10}\Rightarrow x=\frac{4}{5}\\\\0=0\left(loai\right)\end{matrix}\right.\)
Vậy \(x=\frac{4}{5}\)

18 tháng 1 2019

1)6x-8=3x+1

6x-3x=1+8

3x=9

x=3

Vậy x=3

2: 12-10x=25-30x

=>20x=13

=>x=13/20

3: \(3\left(2x+3\right)-2\left(4x-5\right)=10x+21\)

=>6x+9-8x+10=10x+21

=>10x+21=-2x+19

=>12x=-2

=>x=-1/6

4: \(\Leftrightarrow25x-15-6x+12=11-5x\)

=>19x-3=11-5x

=>24x=14

=>x=7/12

5: \(\Leftrightarrow8-12x-5+10x=4-6x\)

=>4-6x=-2x+3

=>-4x=-1

=>x=1/4

6: \(\Leftrightarrow32x-24-6+9x=13-40x\)

=>41x-30=13-40x

=>81x=43

=>x=43/81

7: \(\Leftrightarrow10x-5+20x=5x-11\)

=>30x-5=5x-11

=>25x=-6

=>x=-6/25