Bài 1. tìm x :

a, -16 + 23 + x = -16 

            23 + x = -16-(-16)

            23 + x = 0

                    x = 0 - 23 

            Vậy: x = -23

b, 2x - 35 = 15

    2x       = 15 + 35

    2x       = 50

      x       = 50 : 2

Vậy: x     = 25

c, 3x + 17 = 12

    3x        = 12 - 17

    3x        = -5 

Vậy: x        = -5/3

d, | x - 1 | = 0

      x - 1  = 0

      x       = 0 + 1

Vậy: x     = 1

e, -13 . | x | = -26

    -13 .  x   = -26

             x   = -26 : ( -13 )

     Vậy: x   = 2

Mik làm bài 1 còn bài 2 bn tự làm nha

Hok tốt!!!

Bài 1: 

1) Ta có: \(\left(-12\right)+6\cdot\left(-3\right)\)

\(=-12-18\)

=-30

2) Ta có: \(\left(36-2020\right)+\left(2019-136\right)-27\)

\(=36-2020+2019-136-27\)

\(=1-100-27\)

\(=-126\)

3) Ta có: \(\left(144-97\right)-\left(244-197\right)\)

\(=144-97-244+197\)

\(=-100+100=0\)

4) Ta có: \(\left(-24\right)\cdot13-24\cdot\left(-3\right)\)

\(=-24\cdot13+24\cdot3\)

\(=24\cdot\left(-13+3\right)\)

\(=24\cdot\left(-10\right)=-240\)

5) Ta có: \(54+55+56+57+58-\left(64+65+66+67+68\right)\)

\(=54+55+56+57+58-64-65-66-67-68\)

\(=\left(54-64\right)+\left(55-65\right)+\left(56-66\right)+\left(57-67\right)+\left(58-68\right)\)

\(=\left(-10\right)+\left(-10\right)+\left(-10\right)+\left(-10\right)+\left(-10\right)\)

=-50

6) Ta có: \(24\cdot\left(16-5\right)-16\cdot\left(24-5\right)\)

\(=24\cdot16-24\cdot5-16\cdot24+16\cdot5\)

\(=-24\cdot5+16\cdot5\)

\(=5\cdot\left(-24+16\right)\)

\(=-5\cdot8=-40\)

7) Ta có: \(47\cdot\left(23+50\right)-23\cdot\left(47+50\right)\)

\(=47\cdot23+47\cdot50-23\cdot47-23\cdot50\)

\(=47\cdot50-23\cdot50\)

\(=50\cdot\left(47-23\right)\)

\(=50\cdot24=1200\)

8) Ta có: \(\left(-31\right)\cdot47+\left(-31\right)\cdot52+\left(-31\right)\)

\(=-31\cdot\left(47+52+1\right)\)

\(=-31\cdot100=-3100\)

Bài 2: 

1) Ta có: \(-17-\left(2x-5\right)=-6\)

\(\Leftrightarrow-17-2x+5+6=0\)

\(\Leftrightarrow-2x-6=0\)

\(\Leftrightarrow-2x=6\)

hay x=-3

Vậy: x=-3

2) Ta có: \(10-2\left(4-3x\right)=-4\)

\(\Leftrightarrow10-8+6x+4=0\)

\(\Leftrightarrow6x+6=0\)

\(\Leftrightarrow6x=-6\)

hay x=-1

Vậy: x=-1

3) Ta có: \(-12+3\left(-x+7\right)=-18\)

\(\Leftrightarrow-12-3x+21+18=0\)

\(\Leftrightarrow-3x+27=0\)

\(\Leftrightarrow-3x=-27\)

hay x=9

Vậy: x=9

4) Ta có: \(-45:\left[5\cdot\left(-3-2x\right)\right]=3\)

\(\Leftrightarrow5\cdot\left(-3-2x\right)=-15\)

\(\Leftrightarrow-2x-3=-3\)

\(\Leftrightarrow-2x=0\)

hay x=0

Vậy: x=0

5) Ta có: x(x+3)=0

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

Vậy: \(x\in\left\{0;-3\right\}\)

6) Ta có: (x-2)(x+4)=0

\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x+4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-4\end{matrix}\right.\)

Vậy: \(x\in\left\{2;-4\right\}\)

7) Ta có: \(x\left(x+1\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x+1=0\\x-3=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-1\\x=3\end{matrix}\right.\)

Vậy: \(x\in\left\{0;-1;3\right\}\)

Bài 1: 

1) Ta có: (−12)+6⋅(−3)(−12)+6⋅(−3)

=−12−18=−12−18

=-30

2) Ta có: (36−2020)+(2019−136)−27(36−2020)+(2019−136)−27

=36−2020+2019−136−27=36−2020+2019−136−27

=1−100−27=1−100−27

=−126

Tớ chcs cậu học thật giỏi nha !

Em nến gõ bằng công thức toán học em nhé. Như vậy mọi người nới hiểu đúng đề bài để trợ giúp cho em một cách tốt nhất em ạ!

Mai mk gửi cho

Tính hợp lý : 

45-45.(-12+3)  

=45-45.(-9)

=45-(405)

=kết quả

31.(-18)+31.(-81)-31

=31.(-18)+31.(-81)-31.1

=31.[-18+(-81)+(-1)]

=31.(-100)

Kquả

24.(16-5)-16.(24-5)

=24.16-24.5-16.24-16.5

=(26.16-16.24)-24.5-16.5

=0-(24-16)5

=0-8.5

0-40

(-12).47+(-12).52+(-12).1

=-12.[47+52+1]

=-12.100

=-1200

1)  \(35.18-5.7.28=35.18-35.28=35\left(18-28\right)=-350\)

2)  \(45-5\left(12+9\right)=45-60-45=-60\)

3)  \(24\left(16-5\right)-16\left(24-5\right)=24.16-24.5-16.24+16.5=5\left(16-24\right)=5.8=40\)

4)  \(29\left(19-13\right)-19\left(29-13\right)=29.19-29.13-19.29+19.13=13\left(19-29\right)=-130\)

5)  \(31.\left(-18\right)+31.\left(-81\right)-31=-31.\left(18+81+1\right)=-3100\)

6)  \(\left(-12\right).47+\left(-12\right).52+\left(-12\right)=\left(-12\right)\left(47+52+1\right)=-1200\)

7)  \(13\left(23+22\right)-3\left(17+28\right)=13.45-3.45=45.\left(13-3\right)=450\)

8)  \(-48+48.\left(-78\right)+48.\left(-21\right)=-48\left(1+78+21\right)=-4800\)

dell bt

phải k mình mới làm

a)35.18-5.7.28

=35.18-35.28

=35.(18-28)

=35.(-10)

=-350

NHỚ K ĐÓ

1) 35.18 - 5.7.28

= 35.18 - 35.28

= 35.(18 - 28)

= 35.(-10)

= -350

2) 45 - 5.(12 + 9)

= 45 - 5.12 - 5.9

= 45 - 60 - 45

= (45 - 45) - 60

= 0 - 60

= -60

3) 24.(16 - 5) - 16.(24 - 5)

= 24.16 - 24.5 - 16.24 + 16.5

= (24.16 - 16.24) - (24.5 + 16.5)

= 0 - (24.5 + 16.5)

= -24.5 + 16.5

= 5.(-24 + 16)

= 5.(-8)

= -40

4) 29.(19 - 13) - 19.(29 - 13)

= 29.19 - 29.13 - 19.29 + 19.13

= (29.19 - 19.29) + (19.13 - 29.13)

= 0 + (19.13 - 29.13)

= 19.13 - 29.13

= 13.(19 - 29)

= 13.(-10)

= -130

5) 31.(-18) + 31.(-81) - 31

= 31.(-18 - 81 - 1)

= 31.(-100)

= -3100

6) (-12).47 + (-12).52 + (-12)

= (-12).(47 + 52 + 1)

= (-12).100

= -1200

7) 13.(23 + 22) - 3.(17 + 28)

= 13.45 - 3.45

= 45.(13 - 3)

= 45.10

= 450

8) -48 + 48.(-78) + 48.(-21)

= 48.(-1) + 48.(-78) + 48.(-21)

= 48.(-1 - 78 - 21)

= 48.(-100)

= -4800

Cố gắng lên nhé em Hoàng Mai Hoa

1)35.18-5.7.28

= 35 . 18 - 35 . 28

= 35 . ( 18 - 28 )

= 35 . ( - 10 )

= - 350

a/ 35*18-35*28=35*(-10)=-350

b.45-5.(12+9)=45-45-60=-60

c.24.(16-5) -16.(24-5)= 24.16 - 24.5 - 16.24 - 16.5= 0 -120 - 80= -200

35.18-5.7.28

=35.18-35.28

=35.(18-28)

=35.(-10) =-350

35.18 - 5.7.28

=35.18- 35.28

=35.(18-28)

=35. (-10)

= -350

45-5.(12+9

=45+(-60-45)

=45-60-45

=45-45-60

=0-60

= -60