Câu 1 : 65.(-19)+19.(-24)= (-65).19+19.(-24)=19.[(-65)+(-24)]=19.(-89)=-1691                        
Câu 2:a) 7x.(2+x)-7x(x+3)=14                
            =>7x.(2+x-x-3)=14     
            =>7x.(-1)=14     
            =>(-7).x=14     
            =>x=14:(-7)    
            =>x=-2   
Vậy x=-2

2.(5+3x)+x=31

10+6x+x=31

10+7x=31

  7x=  31-10

7x  =21

x=21:7

x=3

b) (3x-7)+2.(5-2x)+5x=19 

=> 3x - 7 + 10 - 4x + 5x = 19

=> 4x + 3 = 19

=> 4x = 16

=> x = 4

vậy_

a)x=4-12=-8

b)x=19-0=19

c)x=-12+4:2=-4

d)x=6+(-2):2=2

tích mk mk trả lời cho

a, Vì : \(x\in Z\Rightarrow2x-5\in Z\)

\(y\in Z\Rightarrow y-6\in Z\)

Phân tích 19 thành tích hai số nguyên ta có :

   19 = 1.9 = (-1)(-19)

Do đó : ( 2x-5 )( y -6 ) = 1.19 = (-1)(-19)

Ta có bảng sau :

Vậy ...

b, Vì \(\left(x-3\right)\left(x+2\right)< 0\)=> x - 3 và x + 2 khác dấu 

\(\Rightarrow\hept{\begin{cases}x-3< 0\\x+2>0\end{cases}}\) hoặc \(\hept{\begin{cases}x-3>0\\x+2< 0\end{cases}}\)

+) \(\hept{\begin{cases}x-3< 0\\x+2>0\end{cases}}\Rightarrow\hept{\begin{cases}x< 3\\x>-2\end{cases}}\Rightarrow-2< x< 3\)

Mà : x là số nguyên \(\Rightarrow x\in\left\{-1;0;1;2\right\}\)

+) \(\hept{\begin{cases}x-3>0\\x+2< 0\end{cases}}\Rightarrow\hept{\begin{cases}x>3\\x< -2\end{cases}}\Rightarrow3< x< -2\) =>loại

Vậy \(x\in\left\{-1;0;1;2\right\}\)

uk trả lời đi mk k

2x+1=9

2x=8

x=4(thỏa)

\(\sqrt{2x+1}=3\)

nên 2x+1=9

hay x=4

a) \(\left|2x+1\right|-19=-7\)

\(\Rightarrow\left|2x+1\right|=12\)

\(\Rightarrow\orbr{\begin{cases}2x+1=12\\2x+1=-12\end{cases}\Rightarrow}\orbr{\begin{cases}2x=11\\2x=-13\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{11}{2}\\x=\frac{13}{2}\end{cases}}}\)

Vậy \(x\in\left\{\frac{11}{2};\frac{13}{2}\right\}\)

a,\(/2x+1/-19=-7\)

\(=>/2x+1/=-7+19=12\)

\(=>\orbr{\begin{cases}2x+1=12\\2x+1=-12\end{cases}}\)

\(=>\orbr{\begin{cases}x=\frac{12-1}{2}=\frac{11}{2}\\x=\frac{-12-1}{2}=-\frac{13}{2}\end{cases}}\)

b,\(12-2\left(-x+3\right)^2=-38\)

\(=>2\left(-x+3\right)^2=12+38=50\)

\(=>\left(-x+3\right)^2=\frac{50}{2}=25=\pm5^2\)

\(=>\orbr{\begin{cases}-x+3=5\\-x+3=-5\end{cases}}=>\orbr{\begin{cases}-x=2\\-x=-8\end{cases}=>\orbr{\begin{cases}x=-2\\x=8\end{cases}}}\)

b) \(12-2\left(-x+3\right)^2=-38\)

\(\Rightarrow2\left(-x+3\right)^2=50\)

\(\Rightarrow\left(-x+3\right)^2=25\)

\(\Rightarrow\orbr{\begin{cases}\left(-x+3\right)^2=5^2\\\left(-x+3\right)^2=\left(-5\right)^2\end{cases}\Rightarrow\orbr{\begin{cases}-x+3=5\\-x+3=-5\end{cases}}}\)

\(\Rightarrow\orbr{\begin{cases}-x=2\\-x=-8\end{cases}}\Rightarrow\orbr{\begin{cases}x=-2\\x=8\end{cases}}\)

Vậy \(x\in\left\{-2;8\right\}\)

16

a) \(x+546=46\\ x=46-546\\ x=-500\)

b) \(2x-19\times3=27\\ 2x-57=27\\ 2x=27+57\\ 2x=84\\ x=84:2\\ x=42\)

c) \(x+12=23+3\times3^4\\ x+12=23+3\times81\\ x=23+243-12\\ x=254\)

d) \(x-12=3-3\times2^4\\ x-12=3-3\times16\\ x=3-48+12\\ x=-33\)

e) \(\left(27-x\right)\left(x+9\right)=0\\ \Rightarrow\left[{}\begin{matrix}27-x=0\\x+9=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=27\\x=-9\end{matrix}\right.\)

f) \(\left(-x\right)\left(x-43\right)=0\\ \Rightarrow\left[{}\begin{matrix}-x=0\\x-43=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=0\\x=43\end{matrix}\right.\)

a) x + 546 = 46

x = 46 - 546

x = -500

b) 2x - 19 x 3 = 27

2x - 57 = 27

2x = 27 + 57

2x = 84

x = 84 : 2

x = 42

c) x + 12 = 23 + 3 x 3⁴

x + 12 = 23 + 3 x 81

x + 12 = 23 + 243

x + 12 = 266

x = 266 - 12

x = 254

d) x - 12 = 3 - 3 x 2⁴

x - 12 = 3 - 3 x 16

x - 12 = 3 - 48

x - 12 = -45

x = -45 + 12

x = -33

e) (27 - x) x (x + 9) = 0

TH1: 27 - x = 0

x = 27 - 0

x = 27

TH2: x + 9 = 0

x = 0 + 9

x = 9

⇒ x = 27 hoặc x = 9

f) (-x) x (x - 43) = 0

TH1: -x = 0

⇒ x = 0

TH2: x - 43 = 0

x = 0 + 43

x = 43

⇒ x = 0 hoặc x = 43.