a) \(x+5=20-\left(12-7\right)\)

\(\Rightarrow x+5=20-5\)

\(\Rightarrow x+5=15\)

\(\Rightarrow x=15-5\)

\(\Rightarrow x=10\)

b) \(15-\left(3+2x\right)=2^2\)

\(\Rightarrow3+2x=15-4\)

\(\Rightarrow3+2x=11\)

\(\Rightarrow2x=11-3\)

\(\Rightarrow2x=8\)

\(\Rightarrow x=\dfrac{8}{2}\)

\(\Rightarrow x=4\)

c) \(-11-\left(19-x\right)=50\)

\(\Rightarrow19-x=-11-50\)

\(\Rightarrow19-x=-61\)

\(\Rightarrow x=61+19\)

\(\Rightarrow x=80\)

d) \(159-\left(25-x\right)=43\)

\(\Rightarrow25-x=159-43\)

\(\Rightarrow25-x=116\)

\(\Rightarrow x=25-116\)

\(\Rightarrow x=-91\)

e) \(\left(79-x\right)-43=-\left(17-52\right)\)

\(\Rightarrow\left(79-x\right)-43=52-17\)

\(\Rightarrow79-x-43=35\)

\(\Rightarrow36-x=35\)

\(\Rightarrow x=1\)

f) \(\left(7+x\right)-\left(21-13\right)=32\)

\(\Rightarrow7+x-8=32\)

\(\Rightarrow x-1=32\)

\(\Rightarrow x=32+1\)

\(\Rightarrow x=33\)

g) \(-x+20=-15+8+13\)

\(\Rightarrow-x+20=6\)

\(\Rightarrow x=20-6\)

\(\Rightarrow x=14\)

h) \(-\left(-x+13-142\right)+18=55\)

\(\Rightarrow x-13+142+18=55\)

\(\Rightarrow x+147=55\)

\(\Rightarrow x=55-147\)

\(\Rightarrow x=-92\)

a,  2 3 x + 5 2 x = 2 5 2 + 2 3 - 33

8x+25x = 33

33x = 33

x = 1

b,  260 : x + 4 = 5 2 3 + 5 - 3 3 2 + 2 2

260:(x+4) = 5.13–3.13

x+4 = 260:26

x+4 = 10

x = 6

c,  720 : [ 41 - 2 x - 5 ] = 2 3 . 5

41–(2x–5) = 720:40

2x–5 = 41–18

2x = 28

x = 14

d,  3 2 - 2 x - 12 + 35 = 5 2 + 279 : 3 2

7(x–12)+35 = 56

7(x–12) = 21

x–12 = 3

x = 15

`#3107.101107`

a,

`2x + 3x = 5^7 \div 5^5`

$\Rightarrow (2 + 3)x = 5^{7 - 5}$

$\Rightarrow 5x = 5^2$

$\Rightarrow 5x = 25$

$\Rightarrow x = 25 \div 5$

$\Rightarrow x = 5$

Vậy, `x = 5`

b,

`5(7x - 45) = 2^3 . 5^2 - 3^2 . 20`

`\Rightarrow 5(7x - 45) = 8.25 - 9.20`

`\Rightarrow 5(7x - 45) = 40.5 - 36.5`

`\Rightarrow 5(7x - 45) = 5.(40 - 36)`

`\Rightarrow 5(7x - 45) = 5.4`

`\Rightarrow 7x - 45 = 4`

`\Rightarrow 7x = 49`

`\Rightarrow x = 49 \div 7`

`\Rightarrow x = 7`

Vậy, `x = 7.`

A) (2+3).x=5 mũ 2

 5.x=5 mũ 2

5.x=25

x=25:5

x=5 

vậy x=5 

câu B ko bt làm bn ạ

a) 23.25 + 75.23 - 1300

= 23.(25 + 75) - 1300

= 23.100 - 1300

= 2300 - 1300

= 1000

b) 36 : 3² - 5.2²

= 36 : 9 - 5.4

= 4 - 20

= -16

c) 183 + 80 : [20 - 4.(5² - 24)]

= 183 + 80 : [20 - 4.(25 - 24)]

= 183 + 80 : (20 - 4.1)

= 183 + 80 : 16

= 183 + 5

= 188

d) (-125) - [148 + 5.(-25)]

= -125 - (148 - 125)

= -125 - 148 + 125

= (-125 + 125) - 148

= 0 - 148

= -148

a) 23.25 + 75.23 - 1300

= 23. (25+75) - 1300

= 23.100 - 1300

= 2300 - 1300 = 1000

b) 36 : 3² - 5 . 2²

= 36: 9 - 5.4

= 4 - 20 = -16

c) 183 + 80 : [ 20 - 4 ( 5² - 24 ) ]

= 183 + 80: [20 - 4.(25-24)]

= 183 + 80 : [20 - 4.1)]

= 183 + 80: [20 - 4]

= 183 + 80:16

= 183 + 5 = 188

d) (-125) - [148 + 5 . (-25) ]

= -125 - 148 + 125

= (125 - 125) - 148

= 0 - 148 = -148

2² x 4³ - 625 : {[504 - (5² x 8 + 70) : 3² + 6] : 20 + 2023⁰}

= 4 x 64 - 625 : {[504 - (25 x 8 + 70) : 9 + 6] : 20 + 1}

= 256 - 625 : {[504 - (200 + 70) : 9 + 6] : 20 + 1}

= 256 - 625 : {[504 - 270 : 9 + 6] : 20 + 1}

= 256 - 625 : {[504 - 30 + 6] : 20 + 1}

= 256 - 625 : {[474 + 6] : 20 + 1]

= 256 - 625 : {480 : 20 + 1]

= 256 - 625 : {24 + 1}

= 256 - 625 : 25

= 256 - 41

= 215

22 x 43 - 625 : {[504 - (52 x 8 + 70) : 32 + 6] : 20 + 20230}

= 4 x 64 - 625 : {[504 - (25 x 8 + 70) : 9 + 6] : 20 + 1}

= 256 - 625 : {[504 - (200 + 70) : 9 + 6] : 20 + 1}

= 256 - 625 : {[504 - 270 : 9 + 6] : 20 + 1}

= 256 - 625 : {[504 - 30 + 6] : 20 + 1}

= 256 - 625 : {[474 + 6] : 20 + 1]

= 256 - 625 : {480 : 20 + 1]

= 256 - 625 : {24 + 1}

= 256 - 625 : 25

= 256 - 41

= 215

625:25=25 mà

\(\dfrac{2^2}{1\times3}\times\dfrac{3^2}{2.4}\times\dfrac{4^2}{3.5}\times\dfrac{5^2}{4.6}=\dfrac{2^2.3^2.4^2.5^2}{1.3.2.4.3.5.4.6}=\dfrac{2^2.3^2.4^2.5^2}{1.2.3.3.4.4.5.2.3}=\dfrac{2^2.3^2.4^2.5^2}{3^3.2^2.4^2.5.1}=\dfrac{5}{3.1}=\dfrac{5}{3}\)

\(\dfrac{2^2}{1\cdot3}\cdot\dfrac{3^2}{2\cdot4}\cdot\dfrac{4^2}{3\cdot5}\cdot\dfrac{5^2}{4.6}\\ =\dfrac{2^2\cdot3^2\cdot4^2\cdot5^2}{1\cdot3\cdot2\cdot4\cdot3\cdot5\cdot4\cdot6}\\ =\dfrac{2^2\cdot3^2\cdot4^2\cdot5^2}{1\cdot2\cdot4^2\cdot4^2\cdot5\cdot6}\\ =\dfrac{2\cdot5}{6}=\dfrac{5}{3}\)

a) \(3.5^2+15.2^2-26\div2\)

= 3.25 + 15.4 - 13

= 75 + 60 - 13

= 135 - 13

= 122

b) \(5^3.2-100\div4+2^3.5\)

= 125.2 - 25 + 8.5

= 250 - 25 + 40

= 225 + 40

= 265

c)\(6^2\div9+50.2-3^3.33\)

= 36 : 9 + 100 - 9.33

= 4 + 100 - 297

= 104 - 297

= -193

d)\(3^2.5+2^3.10-81\div3\)

= 9.5 + 8.10 - 27

= 45 + 80 - 27

= 125 - 27

= 98

e) \(5^{13}\div5^{10}-25.2^2\)

= 5³ - 25.4

= 125 - 100

= 25

f) \(20\div2^2+5^9\div5^8\)

= 20 : 4 + 5

= 5 + 5

= 10

50 - 52 + 40 - 42 + 30 - 32 + 20 - 22 +10 - 12 + 60

=(50 - 52) + (40 - 42) + (30 - 32) + (20 - 22) +(10 - 12) + 60

=(-2)+(-2)+(-2)+(-2)+(-2)+60

=(-10)+60

50

=50

OLM duyệt đi

=50 nha bn hjhj Cách làm là.....bấm máy tính