Lời giải:

a. 

$(25-2x)^3:5-3^2=4^2$

$(25-2x)^3:5=4^2+3^2=25$

$(25-2x)^3=25.5=5^3$

$\Rightarrow 25-2x=5$

$\Rightarrow 2x=20$

$\Rightarrow x=10$

b.

$2.3^x=10.3^{12}+8.27^4=10.3^{12}+8.3^{12}=18.3^{12}=2.3^{14}$

$\Rightarrow 3^x=3^{14}$

$\Rightarrow x=14$

Lâu rồi mình ko giải, sai thì thôi nhé!

a) \(\left(10-2x\right)^2=25-\left(-11\right)\)'=

\(\Leftrightarrow\left(10-2x\right)^2=36\)

\(\Leftrightarrow\left(10-2x\right)^2=6^2\)

\(\Leftrightarrow\orbr{\begin{cases}10-2x=6\\10-2x=-6\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=10-6\\2x=10-\left(-6\right)\end{cases}\Leftrightarrow}\orbr{\begin{cases}2x=4\\2x=16\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=2\\x=8\end{cases}}}\)

Vậy \(x\in\left\{2;8\right\}\)

b) \(-2\left(-x+5\right)-3\left(5-x\right)=4\left(2+x\right)\)

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

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

\(\Leftrightarrow-25+5x=8+4x\)

\(\Leftrightarrow5x-25=8+4x\)

\(\Leftrightarrow5x=8+4x+25\)

\(\Leftrightarrow5x=4x+33\)

\(\Leftrightarrow5x-4x=33\)

\(\Leftrightarrow1x=33\)

\(\Leftrightarrow x=33\)

Vậy \(x=33\)

a) (10 - 2x)² = 25 - (-11)

(10 - 2x)² = 36

(10 - 2x)² = 6²

=> 10 - 2x = 6

2x = 10 - 6

2x = 4

x =4:2

x=2

Vậy x = 2

b)-2(-x+5) - 3(5 - x) = 4(2+x)

2x - 10 - 15 +3x = 8 + 4x

2x - 25 + 3x = 8 +4x

2x + 3x - 4x = 8 + 25

5x - 4x = 33

x= 33

Vậy x = 33

Ta có :

(10 - 2x ) ² =25-(-11)

(10-2x)²=36

(10-2x)²=6²

10-2x=6

2x=10-6

2x=4

x=4:2

x=2

b) Ta có :

-2(-x+5)-3(5-x)=4(2+x)

(-2(-x))+(-2x5)-(-3x5)-(-3(x))=8+4x

2x+(-10)-(-15)-(-3x)=8+4x

2x+3x-10+15=8+4x

5x+(15-10)=8+4x

5x+5=8+4x

5x-4x=5+8

x=13

\(\frac{x-2}{27}+\frac{x-3}{26}+\frac{x-4}{25}+\frac{x-5}{24}+\frac{x-44}{5}=1\)

\(\Leftrightarrow\left(\frac{x-2}{27}-1\right)+\left(\frac{x-3}{26}-1\right)+\left(\frac{x-4}{25}-1\right)+\left(\frac{x-5}{24}-1\right)\)\(+\left(\frac{x-44}{5}+3\right)=1-1\)

\(\Leftrightarrow\frac{x-29}{27}+\frac{x-29}{26}+\frac{x-29}{25}+\frac{x-29}{24}\)\(+\frac{x-29}{5}=0\)

\(\Leftrightarrow\left(x-29\right)\left(\frac{1}{27}+\frac{1}{26}+\frac{1}{25}+\frac{1}{24}+\frac{1}{5}\right)=0\)

Mà \(\frac{1}{27}+\frac{1}{26}+\frac{1}{25}+\frac{1}{24}+\frac{1}{5}\ne0\)

=> x - 29 = 0

=> x = 29.

a)\(-17+\left|5-x\right|=10\)

\(\Leftrightarrow\left|5-x\right|=10-\left(-17\right)\)

\(\Leftrightarrow\left|5-x\right|=10+17\)

\(\Leftrightarrow\left|5-x\right|=27\)

\(\Leftrightarrow\orbr{\begin{cases}5-x=27\\5-x=-27\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=-22\\x=32\end{cases}}\)

b) \(45-5\left|12-x\right|=125\div\left(-25\right)\)

\(\Leftrightarrow45-5\left|12-x\right|=-5\)

\(\Leftrightarrow5\left|12-x\right|=45-\left(-5\right)\)

\(\Leftrightarrow5\left|12-x\right|=45+5\)

\(\Leftrightarrow5\left|12-x\right|=50\)

\(\Leftrightarrow\left|12-x\right|=10\)

\(\Leftrightarrow\orbr{\begin{cases}12-x=10\\12-x=-10\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=22\end{cases}}\)

c) \(2< \left|3-x\right|\le5\)

\(\Leftrightarrow\left|3-x\right|\in\left\{3;4;5\right\}\)

* \(\left|3-x\right|=3\Leftrightarrow\orbr{\begin{cases}3-x=3\\3-x=-3\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\x=6\end{cases}}}\)

* \(\left|3-x\right|=4\Leftrightarrow\orbr{\begin{cases}3-x=4\\3-x=-4\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-1\\x=7\end{cases}}}\)

* \(\left|3-x\right|=5\Leftrightarrow\orbr{\begin{cases}3-x=5\\3-x=-5\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-2\\x=8\end{cases}}}\)

d) \(\left|x+4\right|< 3\)

mà \(\left|x+4\right|\ge0\)

\(\Rightarrow\left|x+4\right|\in\left\{0;1;2\right\}\)

* \(\left|x+4\right|=0\Leftrightarrow x+4=0\Leftrightarrow x=-4\)

* \(\left|x+4\right|=1\Leftrightarrow\orbr{\begin{cases}x+4=1\\x+4=-1\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-3\\x=-5\end{cases}}}\)

* \(\left|x+4\right|=2\Leftrightarrow\orbr{\begin{cases}x+4=2\\x+4=-2\end{cases}\Leftrightarrow\orbr{\begin{cases}x=-2\\x=-6\end{cases}}}\)

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a, 2x + 35 -x+27=0

   x +62=0

x=-62

b, 2x -41 -3x + 23 =0

-x -18=0

-x=18

x=-18

c, 4x -12-3x-15= -124

x -27=-124

x= -97

d, Suy ra x+3 =0 hoặc 2x-18=0

               x=-3   hoặc  2x=18 => x=9

vậy x=-3 hoặc x=9

k minh minh giai cho

Ggh

\(\left(x-3\right)\left(x-12\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-3=0\\x-12=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=3\\x=12\end{cases}}\)

\(\Rightarrow x\in\left\{3;12\right\}\)

\(\left(x^2-81\right)\left(x^2+9\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x^2-81=0\\x^2+9=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=9\\x\in\varnothing\end{cases}}\Leftrightarrow x=9\)

\(\Rightarrow x=9\)

\(\left(x-4\right)\left(x+2\right)< 0\)

\(\Rightarrow\hept{\begin{cases}x-4\\x+2\end{cases}}\)trái dấu

\(TH1:\hept{\begin{cases}x-4>0\\x+2< 0\end{cases}}\Leftrightarrow\hept{\begin{cases}x>4\\x< -2\end{cases}}\Leftrightarrow x\in\varnothing\)

\(TH2:\hept{\begin{cases}x-4< 0\\x+2>0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x< 4\\x>-2\end{cases}}\Leftrightarrow x\in\left\{-1;0;1;2;3\right\}\)

Vậy \(x\in\left\{-1;0;1;2;3\right\}\)

`a,`

\((- 5) .x + 17 = - 23\)

`\Rightarrow (-5)x = -23 - 17`

`\Rightarrow (-5)x =-40`

`\Rightarrow x = (-40) \div (-5)`

`\Rightarrow x = 8`

Vậy,` x = 8`

`b,`

\(8 + 4x = - 24\)

`\Rightarrow 4x = -24 - 8`

`\Rightarrow 4x = -32`

`\Rightarrow x = -32 \div 4`

`\Rightarrow x = -8`

Vậy, `x = -8`

`c,`

\(32 – 12 + x = -10\)

`\Rightarrow 20 + x = -10`

`\Rightarrow x = -10 - 20`

`\Rightarrow x = -30`

Vậy, `x = -30`

`d,`

\(x – 87 + 13 = - 100\)

`\Rightarrow x - 87 = -100 - 13`

`\Rightarrow x - 87 = -113`

`\Rightarrow x = -113 + 87`

`\Rightarrow x = -26`

Vậy, `x = -26.`