a. \(\left|x-3\right|-7=13\Leftrightarrow\left|x-3\right|=20\)

TH1: \(x-3=20\Leftrightarrow x=23\)

TH2: \(x-3=-20\Leftrightarrow x=-17\)

b. \(72-3.\left|x+1\right|=9\Leftrightarrow\left|x+1\right|=21\)

TH1: \(x+1=21\Leftrightarrow x=20\)

TH2: \(x+1=-21\Leftrightarrow x=-22\)

c. \(17-\left(43-\left|x\right|\right)=45\Leftrightarrow\left|x\right|=71\)

TH1: \(x=71\)

TH2: \(x=-71\)

d. \(3\left|x-1\right|-5=7\Leftrightarrow\left|x-1\right|=4\)

TH1: \(x-1=4\Leftrightarrow x=5\)

TH2: \(x-1=-4\Leftrightarrow x=-3\)

e. \(-12\left(x-5\right)+7\left(3-x\right)=5\Leftrightarrow-12x+60+21-7x=5\Leftrightarrow-19x=-76\Leftrightarrow x=4\)

a.

\(\left|x-3\right|-7=13\)

\(\left|x-3\right|=13+7\)

\(\left|x-3\right|=20\)

\(x-3=\pm20\)

• \(x-3=20\)

               \(x=20+3\)

               \(x=23\)

• \(x-3=-20\)

               \(x=-20+3\)

               \(x=-17\)

Vậy x = 23 hoặc x = - 17.

b.

\(72-3\times\left|x+1\right|=9\)

\(3\times\left|x+1\right|=72-9\)

\(3\times\left|x+1\right|=63\)

\(\left|x+1\right|=63\div3\)

\(\left|x+1\right|=21\)

\(x+1=\pm21\)

• \(x+1=21\)

               \(x=21-1\)

               \(x=20\)

• \(x+1=-21\)

               \(x=-21-1\)

               \(x=-22\)

Vậy x = 20 hoặc x = - 22.

c.

\(17-\left(43-\left|x\right|\right)=45\)

\(43-\left|x\right|=17-45\)

\(43-\left|x\right|=-28\)

\(\left|x\right|=43-\left(-28\right)\)

\(\left|x\right|=71\)

\(x=\pm71\)

Vậy x = 71 hoặc x = - 71.

d.

\(3\times\left|x-1\right|-5=7\)

\(3\times\left|x-1\right|=7+5\)

\(3\times\left|x-1\right|=12\)

\(\left|x-1\right|=12\div3\)

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

\(x-1=\pm4\)

• \(x-1=4\)

               \(x=4+1\)

               \(x=5\)

• \(x-1=-4\)

               \(x=-4+1\)

               \(x=-3\)

Vậy x = 5 hoặc x = - 3.

e.

\(-12\times\left(x-5\right)+7\times\left(3-x\right)=5\)

\(-12\times x+\left(-12\right)\times\left(-5\right)+7\times3-7\times x=5\)

\(-12\times x+60+21-7\times x=5\)

\(-19\times x+81=5\)

\(-19\times x=5-81\)

\(-19\times x=-76\)

\(x=\frac{-76}{-19}\)

\(x=4\)

Chúc bạn học tốt

b ) 3 - ( x - 5 ) = - 7 + ( - 8 )

     3 - ( x - 5 ) = - 15

            x - 5   = 3 - ( - 15 )

            x - 5   = 18

                 x   = 18 + 5

                 x   = 23

Vậy x = 23

Bài 2: 

a: =>x=0 hoặc x+3=0

=>x=0 hoặc x=-3

b: =>x-2=0 hoặc 5-x=0

=>x=2 hoặc x=5

c: =>x-1=0

hay x=1

1/a)Ta có -5=-1*5=-5*1

​Sau đó bn lập bảng rồi dùng ước bội để tính nhé​

​ Tk mình nha bn!

\(b,\Leftrightarrow\left(x-5\right)\left(x-4\right)\left(x+4\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=5\\x=4\\x=-4\end{matrix}\right.\\ c,\Leftrightarrow x-2015>0\Leftrightarrow x>2015\\ d,\Leftrightarrow\left[{}\begin{matrix}\left\{{}\begin{matrix}3-x>0\\x+6>0\end{matrix}\right.\\\left\{{}\begin{matrix}3-x< 0\\x+6< 0\end{matrix}\right.\end{matrix}\right.\Leftrightarrow-6< x< 3\)

x=5

BS: \(x\in \mathbb{Z}\)

\(a,\Rightarrow x\in\left\{1;2;3;4\right\}\\ b,\Rightarrow x\in\left\{-3;-2;-1\right\}\\ d,\Rightarrow x\in\left\{-1;-2;-3;...\right\}\\ e,\Rightarrow x\in\left\{-4;-5;-6;...\right\}\)

a.\(x\in\left\{1;2;3;4\right\}\)
b.\(x\in\left\{-3;-2;-1\right\}\)
 

a)56-(x+5):2=40

   (x+5):2=56-40

   (x+5):2=16

   x+5=16:2

   x+5=8

       x=8-5

       x=3

Vậy x=3

b)|x+2|=3³

   |x+2|=27

\(\Rightarrow\orbr{\begin{cases}x+2=27\\x+2=-27\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=27-2=25\\x=-27-2=-29\end{cases}}\)

Vậy x = 25 hoặc x = -29

\(a,56-\left(x+5\right):2=40\)

\(56-\left(x+5\right)=80\)

\(x+5=-24\Leftrightarrow x=-29\)

\(b,|x+2|=3^3\)

\(|x+2|=27\)

\(Th1:x+2=27\Leftrightarrow x=25\)

\(Th2:x+2=-27\Leftrightarrow x=-29\)

Lời giải:
a. $(x^2-9)(5x+15)=0$

$\Rightarrow x^2-9=0$ hoặc $5x+15=0$
Nếu $x^2-9=0$

$\Rightarrow x^2=9=3^2=(-3)^2$

$\Rightarrow x=3$ hoặc $-3$
Nếu $5x+15=0$

$\Rightarrow x=-3$
b.

$x^2-8x=0$
$\Rightarrow x(x-8)=0$

$\Rightarrow x=0$ hoặc $x-8=0$

$\Rightarrow x=0$ hoặc $x=8$

c. 

$5+12(x-1)^2=53$

$12(x-1)^2=53-5=48$

$(x-1)^2=48:12=4=2^2=(-2)^2$

$\Rightarrow x-1=2$ hoặc $x-2=-2$
$\Rightarrow x=3$ hoặc $x=0$

d.

$(x-5)^2=36=6^2=(-6)^2$
$\Rightarrow x-5=6$ hoặc $x-5=-6$

$\Rightarrow x=11$ hoặc $x=-1$

e.

$(3x-5)^3=64=4^3$

$\Rightarrow 3x-5=4$

$\Rightarrow 3x=9$

$\Rightarrow x=3$

f.

$4^{2x}+2^{4x+3}=144$
$2^{4x}+2^{4x}.8=144$

$2^{4x}(1+8)=144$

$2^{4x}.9=144$

$2^{4x}=144:9=16=2^4$

$\Rightarrow 4x=4\Rightarrow x=1$