Bài 1

a) 15 + 4.12 - 3²

=15 + 48 - 9

= 63 - 9

= 54

b) {[(37 + 13) : 5].2 - 45 : 5}.7 - 2022⁰

= [(50 : 5).2 - 9].7 - 1

= (10.2 - 9).7 - 1

= (20 - 9).7 - 1

= 11.7 - 1

= 77 - 1

= 76

Bài 2

a) 13x + 3 = 16

13x = 16 - 3

13x = 13

x = 13 : 13

x = 1

b) 2x - 138 = 2⁴ : 2³

2x = 2 + 138

2x = 140

x = 140 : 2

x = 70

a) 

\(13x+3=16\\ 13x=16-3\\ 13x=13\\ x=13:13\\ x=1\)

b) 

\(2x-138=2^4:2^3\\ 2x-138=2\\ 2x=2+138\\ 2x=140\\ x=140:2\\ x=70\)

a) 

b) 

a) \(6⋮\left(x-1\right)\left(đkxđ:x\ne1;x\inℕ\right)\)

\(\Rightarrow x-1\in U\left(6\right)=\left\{1;2;3;6\right\}\)

\(\Rightarrow x\in\left\{2;3;4;7\right\}\)

b) \(14⋮\left(2x+3\right)\left(đkxđ:x\ne-\dfrac{3}{2};x\inℕ\right)\)

\(\Rightarrow2x+3\in U\left(14\right)=\left\{1;2;7;14\right\}\)

\(\Rightarrow x\in\left\{-1;-\dfrac{1}{2};2;\dfrac{9}{2}\right\}\)

\(\Rightarrow x\in\left\{-2\right\}\)

\(a,6⋮\left(x-1\right)\\ \Rightarrow\left(x-1\right)\inƯ\left(6\right)=\left\{\pm1;\pm2;\pm3;\pm6\right\}\\ Ta.có:x-1=-6\Rightarrow x=-5\left(loại\right)\\ x-1=-3\Rightarrow x=-2\left(loại\right)\\ x-1=-2\Rightarrow x=-1\left(loại\right)\\ x-1=-1\Rightarrow x=0\left(nhận\right)\\ x-1=1\Rightarrow x=2\left(nhận\right)\\ x-1=2\Rightarrow x=3\left(nhận\right)\\ x-1=3\Rightarrow x=4\left(nhận\right)\\ x-1=6\Rightarrow x=7\left(nhận\right)\\ Vậy:x\in\left\{0;2;3;4;7\right\}\)

a, 13.(x-9)=169

           x-9  =169:13

           x-9  =13

b, 230+[16+(x,-5)]=315.2\(^3\)

     230+[16+(x,-5)]=2520

               16+(x,-5)=2520-230

                16+(x-5)=2290

                        x-5  =2290-16

                        x-5  =2274

                        x      =2274+5

                        x      =2279

 c, 13x-3\(^2\)x=2003\(^1\)+1\(^{2016}\)

      13x-9x=2004

      (13-9)x=2004

           4 . x=2004

                 x=2004:4

                 x=501

ai giúp minh đi cần quá gấp

\(\text{1) -5x - (-3)= 13}\)

\(\Rightarrow-5x=10\)

\(x=10:-5\)

\(x=-2\)

\(\text{2) |x-3| - 7= 13}\)

\(\Rightarrow|x-3|=20\)

\(\Rightarrow\orbr{\begin{cases}x-3=20\\x-3=-20\end{cases}\Leftrightarrow\orbr{\begin{cases}x=23\\x=-17\end{cases}}}\)

\(\text{3) 17- (43 - |x|)= 45}\)

\(\Rightarrow43-|x|=-28\)

\(|x|=71\)

\(\Rightarrow\orbr{\begin{cases}x=71\\x=-71\end{cases}}\)

\(\text{5) (x-2).(x+15)= 0}\)

\(\Rightarrow\orbr{\begin{cases}x-2=0\\x+15=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=2\\x=-15\end{cases}}}\)

4,\(\text{4) (x-3).(x-5) < 0}\)\(\left(x-3\right).\left(x-5\right)< 0\)

\(\Rightarrow\left(x-3\right)\)và \(\left(x-5\right)\)trái dấu

Mà \(\left(x-3\right)>\left(x-5\right)\Rightarrow\left(x-3\right)>0\)và \(\left(x-5\right)< 0\)

\(+,x-3>0\Rightarrow x>3\)

\(+,x-5< 0\Rightarrow x< 5\)

\(\Rightarrow3< x< 5\)

\(\)Mà \(x\in Z\)

\(\Rightarrow x=4\)

học tốt

1<=>-5x+3=13

<=>-5x=10

<=>x=-2

2<=>|x-3|=20

th1:x-3=20

<=>x=23

th2:x-3=-20

<=>x=-17

3,<=>17-43+|x|=45

<=>|x|=71

th1:x=71

th2:x=-71

4<=>x-3<0                  x-5>0

<=>x<3                       x>5(loại vì ko có số naod vừa lớn hơn 5 và nhỏ hơn 3)

<=>x-3>0                   x-5<0

<=>x>3                      x<5

=>3<x<5

5,<=>x-2=0                  x+15=0

<=>x=2                       x=-15

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