a, 36:(x–5) =  2 2

(x–5) = 9

x = 14

b, [3.(70–x)+5]:2 = 46

[3.(70–x)+5] = 92

70–x = 29

x = 41

c, 450:[41–(2x–5)] =  3 2 .5

41–(2x–5) = 10

2x–5 = 31

2x = 36

x = 18

d, 230+[ 2 4 +(x–5)] = 315. 2018 0

16+(x–5) = 315–230

x–5 = 85–16

x = 69+5

x = 74

e,  2 x + 2 x + 1  = 48

2 x .(2+1) = 48

2 x = 16 =  2 4

x = 4

f,  3 x + 2 + 3 x  = 2430

3 x . 3 2 + 1 = 2430

3 x = 2430:10 = 243 =  3 5

x = 5

d , ( x : 7 + 15 ) . 23 + 391 => Đề thiếu

e , ( 19 . x + 2 . 5² ) : 14 = ( 13 - 8 ) ² - 4²

=> ( 19 . x + 2 . 5² ) : 14 = 5² -  16

=> ( 19 . x + 2 . 5² ) : 14 = 25 - 16 = 9

=> 19 . x + 2 . 52 = 9 x 14 = 126

=> 19 . x + 2 . 25 = 126

=> 19 . x + 50 = 126

=> 19 . x = 126 - 50 = 76

=> x = 76 : 19 = 4

a, 230 + [ 2⁴ + ( x - 5 ) ] = 315 . 2020⁰

=> 230 + [16 + ( x - 5 ) ] = 315 . 1

=> 230 + [ ( 16 - 5 ) + x ) = 315

=> 11 + x = 315 - 230 = 85

=> x = 85 - 11 = 74

b, 707 : [ ( 2^x - 5 ) + 74 ] = 4² - 3²

=> 707 : [ ( 2^x - 5 ) + 74 ] = 16 - 9 = 7

=> ( 2^x - 5 ) + 74 = 707 : 7 = 101

=> 2^x - 5 = 101 - 74 = 27

=> 2^x = 27 + 5 = 32

=> 2^x = 2⁵

=> x = 5

\(a,\Leftrightarrow6x-9+4-2x=-3\Leftrightarrow4x=2\Leftrightarrow x=\dfrac{1}{2}\\ b,\Leftrightarrow\left(x-2021\right)\left(x-6\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2021\\x=6\end{matrix}\right.\\ c,\Leftrightarrow\left(2x-3-6x\right)\left(2x-3+6x\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}-3-4x=0\\8x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{3}{4}\\x=\dfrac{3}{8}\end{matrix}\right.\)

a 

\(230+\left[16+\left(y-5\right)\right]=315\cdot1\)   

\(230+\left[16+\left(y-5\right)\right]=315\)   

\(16+\left(y-5\right)=315-230\)   

\(16+\left(y-5\right)=85\)   

\(y-5=85-16\)   

\(y-5=69\)   

\(y=69+5\)   

\(y=74\)   

b 

\(707:\left[\left(2^y-5\right)+74\right]=16-9\)   

\(707:\left[\left(2^y-5\right)+74\right]=7\)   

\(\left(2^y-5\right)+74=707:7\)  

\(\left(2^y-5\right)+74=101\)   

\(2^y-5=101-74\)   

\(2^y-5=27\)   

\(2^y=27+5\)   

\(2^y=32\)   

\(2^y=2^5\)   

\(\Rightarrow y=5\)

a) \(x\left(x+2021\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+2021=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-2021\end{cases}}\).

b) \(\left(x-2020\right)\left(x+2021\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-2020=0\\x+2021=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=2020\\x=-2021\end{cases}}\).

c) \(\left(x-2021\right)\left(x^2+1\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-2021=0\\x^2+1=0\end{cases}}\Leftrightarrow x=2021\).

d) \(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+...+\left(x+99\right)=0\)

Xét tổng: \(A=1+3+5+...+99\)

Số số hạng của dãy số là: \(\frac{99-1}{2}+1=50\).

Tổng của dãy là: \(A=\left(99+1\right)\times50\div2=2500\).

\(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+...+\left(x+99\right)=0\)

\(\Leftrightarrow50x+2500=0\)

\(\Leftrightarrow x=-50\).

a,

13[x-9] = 169

=> x - 9 = 169/13

=> x - 9 = 13

=> x = 13+9

=> x = 22

b,

Viết lại đề:

7^x+3 = 343

<=> 7^x+3 = 7³

=> x + 3 = 3 

=> x = 3-3

=> x = 0

c,

230 + [16 + [x-5]] = 315 . 2³

=> 230 + [16 + x - 5] = 315 . 8

=> 230 + 16 + x - 5 = 2520

=> 230 + 16 + x = 2520 + 5 = 2525

=> x = 2525 - 230 - 16 = 2279

d,

13.x - 3².x = 2017¹ - 1²⁰¹⁸

=> 13x - 9x = 2017 - 1

=> 4x = 2016

=> x = 504

a) 13 ( x-9 )=169

=> x-9 =169 : 13 =13

=> x=13+9 =22

b)\(7^{x+3}=343\)

\(7^x.7^3=343\)

\(7^x=343:7^3\)

\(7^x=1\Rightarrow x=1\)

c)230 + 16 +x -5 =315.8

241 +x =2520

x=2520-241=2279

d) 13x -\(3^2.x\)=2017-1

x(13-9)=2016

x.4=2016

x=2016:4

x=504

a) (2010 - x)(x + 2021) = 0

<=> \(\left[{}\begin{matrix}2010-x=0\\x+2021=0\end{matrix}\right.\)<=> \(\left[{}\begin{matrix}x=2010\\x=-2021\end{matrix}\right.\)

b) (x - 2)^2 + 5(x - 2) = 0

<=> x^2 - 4x + 4 + 5x - 10 = 0

<=> x^2 + x - 6 = 0

<=> x^2 - 2x + 3x - 6 = 0

<=> x(x - 2) + 3(x - 2) = 0

<=> (x + 3)(x - 2) = 0

<=> \(\left[{}\begin{matrix}x+3=0\\x-2=0\end{matrix}\right.\) <=> \(\left[{}\begin{matrix}x=-3\\x=2\end{matrix}\right.\)

Câu c hình như sai đề hay sao ý?

\(a,Sửa:2021x-1+2022x\left(1-2021x\right)=0\\ \Leftrightarrow\left(2021x-1\right)\left(1-2022x\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2021}\\x=\dfrac{1}{2022}\end{matrix}\right.\)

a)x=0+45

x=45

b)x=23:23=1

x=42-1

x=41

c)x=613+5=618

x=618:6

x=13

a)x=45

b)x=41

c)x=103

d)x=111

e)x=60

g)x=5

h)x=3^x=26