a) [ 316 – ( 25 . 4 + 16 )] : 8 – 24

=( 316 – 116 ) : 8 – 24 = 200 ∶ 8 – 24 = 25 – 24 = 1

b) | -15| + (-27) + 8 + | - 23|

= 15 – 27 + 8 + 23 = 19

c)  5 8   :   5 6   +   2 2   .   3 3   -   2010 0  =  5 2 + 4 . 27 – 1 = 25 + 108 – 1 = 132

\(79+58-23+29+56-79\)

\(=\left(79-79\right)+\left(58-23\right)+\left(29+56\right)\)

\(=0+35+85\)

\(=120\)

          119 nhé bạn

              ~học tốt~

\(79+58-23+29+56-79\)

\(=\)\(79-79+\left(58-23\right)+\left(56+29\right)\)

\(=0+25+85\)

\(=110\)

a) 5.2² + (x + 3) = 5²

5.4 + (x + 3) = 25

20 + (x + 3) = 25

x + 3 = 25 – 20

x + 3 = 5

x = 5 – 3 = 2

b) 2³ + (x – 3²) = 5³ - 4³

8 + (x – 9) = 125 – 64

8 + (x – 9) = 61

x – 9 = 61 – 8

x – 9 = 53

x = 53 + 9 = 62

a) \(5.2^2+\left(x+3\right)=5^2\)

\(x+3=5^2-5.2^2\)

\(x+3=25-20\)

\(x+3=5\)

\(x=2\)

b) \(2^3+\left(x-3^2\right)=5^3-4^3\)

\(8+\left(x-9\right)=125-64\)

\(x-9=53\)

\(x=62\)

(-17) + 42 +(-183) + 58

=[(-17)+(-183)] + (42+58)

=(-200) + 100

=(-100)

cho mik rùi mik giải tiếp

( -17 ) + 42 + ( -183 ) + 58

= ( -17 ) + ( -183 ) + ( 42 + 58 )

= -200 + 100

= -100

125 ( -21 ) + 21 . 225

= 125 ( -21 ) - ( -21 ) 225

= -21 ( 125 - 225 ) 

= -21 . ( -100 )

= 2100

37 ( 13 - 5 ) - 13 ( 37 - 5 )

= 37.13 -37.5 - 13.37 - 13.5

= ( 37.13 - 13.37 ) - ( 37.5 + 13.5 )

= 0 - 5 ( 37 + 13 )

= 0 - 5. 50

= -250

25 - 25 \(\orbr{ }\)23 + 7( -59 + 56 ) + \(|\)-12\(|\):( -4 )

25 -25 ( 23 + 7 . -3 ) + 12 : (-4)

25 - 25 . -2 + -3

= 25 -( -50 ) + ( -3 )

= 72

Bài a) Đúng rồi

b)  (-1).125.21+ 21.225

= - 125.21 + 21.225

= 21 (-125 +225)

= 21.100 = 2100

c) 37.13 - 37.5 - 13.37 + (-13).(-5)

= -185 + 65 = -120

d) 25 - 25.[23 +7.(-3)] + 12: (-4)

= 25 - 25. 2 -3

= 25 -50 -3

= -25-3

=-28

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 !

a) \(227+50+23=\left(227+23\right)+50=250+50=300\)

b) \(135+360+65+40=\left(135+65\right)+\left(360+40\right)=200+400=600\)

c) \(1+2+3+4+5+...+97+98+99+100\)

\(=\left(100+1\right)+\left(99+2\right)+...+\left(50+51\right)\)

\(=101+101+101+...+101\)

\(=101\cdot50\)

\(\Leftrightarrow5050\)

d) \(115\cdot13-13\cdot15=13\cdot\left(115-15\right)=13\cdot100=1300\)

e) \(50-49+48-47+...+4-3+2-1\)

\(=\left(50-49\right)+\left(48-47\right)+...+\left(2-1\right)\)

\(=1+1+1+1+..+1\)

\(=1\cdot25\)

\(=25\)

f) \(30\cdot40\cdot50\cdot60=10\cdot3+10\cdot4+10\cdot5+10\cdot6\)

\(=10\cdot10\cdot10\cdot10\cdot3\cdot4\cdot5\cdot6\)

\(=10000\cdot360\)

\(=3600000\)

g) \(27\cdot36+27\cdot64=27\cdot\left(36+64\right)=27\cdot100=2700\)

h) \(5\cdot2^2-18:3=5\cdot4-18:3=20-6=14\)

i) \(13\cdot17-256:16+14:7-2021^0\)

\(=13\cdot17-4^4:4^2+2-1\)

\(=13\cdot17-16+2-1\)

\(=13\cdot17-17\)

\(=17\cdot\left(13-1\right)\)

\(=204\)

j) \(7^2-36:3=49-12=37\)

a) – 1 < x < 49 18 =>  x ∈ {0;1;2}

b) − 1 24 < x 24 < 1 14  => x = 0

c) 2 3 ≤ x ≤ 26 5 => x ∈ {1;2;3;4;5}

d) 0 < x  ≤ 1 => x = 1