2x-15=17                                          

2x=17+15

2x=32

x=32:2

x=16

1)

a) 2x + 5 = 3⁴ : 3²

2x + 5 = 3²

2x + 5 = 9

2x = 9 - 5

2x = 4

x = 4 : 2

x = 2

b) (3x - 24).73 = 2.74

(3x - 24).73 = 148

3x - 24 = 148/73

3x = 148/73 + 24

3x = 1900/73

x = 1900/73 : 3

x = 1900/219

c) [3.(42 - x)] + 15 = 23.3

126 - 3x + 15 = 69

141 - 3x = 69

3x = 141 - 69

3x = 72

x = 72 : 3

x = 24

d) 126 + (132 - x) = 300

132 - x = 300 - 126

132 - x = 174

x = 132 - 174

x = -42

2)

a) 120 - (x + 55) = 60

x + 55 = 120 - 60

x + 155 = 60

x = 60 - 55

x = 5

b) (7x - 11).3 = 25.52 + 200

(7x - 11).3 = 1500

7x - 11 = 1500 : 3

7x - 11 = 500

7x = 500 + 11

7x = 511

x = 511 : 7

x = 73

c) 2x + 2x + 4 = 544

4x = 544 - 4

4x = 540

x = 540 : 4

x = 135

3) 

a) 10 + 2x = 49 : 47

10 + 2x = 49/47

2x = 49/47 - 10

2x = -421/47

x = -421/47 : 2

x = -421/94

b) 70 - 5(x - 3) = 45

5(x - 3) = 70 - 45

5(x - 3) = 25

x - 3 = 25 : 5

x - 3 = 5

x = 5 + 3

x = 8

c) 4 + 95 : x = 143 : 142 - 23

4 + 95 : x = -3123/142

95 : x = -3123/142 - 4

95 : x = -3691/142

x = 95 : (-3691/142)

x = -13490/3691

\(\left(7x-11\right)^3=2^5\cdot5^2+200\cdot2023^0\\ \left(7x-11\right)^3=32\cdot25+200\cdot1\\ \left(7x-11\right)^3=1000\\ \left(7x-11\right)^3=10^3\\ 7x-11=10\\ 7x=21\\ x=\dfrac{21}{7}=3\)

Lời giải:

$(7x-11)^3=2^5.5^2+200.2023^0=32.25+200=1000=10^3$

$\Rightarrow 7x-11=10$

$\Rightarrow 7x=21$

$\Rightarrow x=3$

(7x - 11)³ = 2⁵.5² + 200

<=> (7x - 11)³  = 32.25 + 200

<=> (7x - 11)³ = 800 + 200

<=> (7x - 11)³ = 1000

<=> (7x - 11)³ = 10³

<=> 7x - 11 = 10

<=> 7x = 21

<=> x = 3 

X=0 

Vì 2 mũ 5 = 32

2 mũ 2 = 4

Suy ra 2 mũ 5 + 2 mũ 2 +200 = 32+4+200=236

* ước của 236 = (1;2;4;59;118;236)

* Mà chỉ có 59+11=70 có chữ số đầu tiên là 7 

ĐÚNG THÌ TICK CHO MÌNH NHA

720 : [41-(2x-5)] =2^3 . 5

<=> 41-(2x-5)=720:40=18

<=> 2x-5=41-18=23

<=>2x=23+5=28

<=> x=28:2=14

2^x-15=17

<=> 2^x=17+15=32

<=> 2^x=2^5

<=> x=5

(7x-11)^3= 2^5.5^2+200

<=> (7x-11)^3=1000

<=> (7x-11)^3=10^3

<=> 7x-11=10

<=> 7x=10+11=21

<=> x=21:7=3

2^x-15=17 nhe. Minh viet nham

tìm số tự nhiên x biết

a, 2^x - 15 =17

=> 2^x = 17 + 15 = 32

=> 2^x = 2⁵

=> x = 5

b, ( 7x - 11)³ = 2⁵ x 5²+200

=> ( 7x - 11 )³ = 32 . 25 + 200

=> ( 7x - 11 )³ = 1000

=> ( 7x - 11 )³ = 10³

=> 7x - 11 = 10

=> 7x = 10 + 11 = 21

=> x = 21 : 7 = 3

a) x=60

b) x=107

f) x=2

.....

CHO MÌNH BIẾT CẢ CÁCH LÀM NHA

a) 315 + ( 146 - x ) = 401

<=> 146 - x = 401 - 315

<=> 146 - x = 86

<=> x = 60

Vậy x  = 60

a) \(2^x-15=17\)

\(2^x=17+15\)

\(2^x=32\)

\(\Rightarrow2^x=2^5\)

\(\Rightarrow x=5\)

b) \(27.3^x=243\)

\(3^x=243:27\)

\(3^x=9\)

\(\Rightarrow3^x=3^2\)

\(\Rightarrow x=2\)

c) \(3^x+25=26.2^2+2.3^0\)

\(3^x+25=104+2\)

\(3^x+25=106\)

\(3^x=106-25\)

\(3^x=81\)

\(\Rightarrow3^x=3^4\)

\(\Rightarrow x=4\)

d) \(\left(7x-11\right)^3=2^5.5^2+200\)

\(\left(7x-11\right)^3=800+200\)

\(\left(7x-11\right)^3=1000\)

\(\Rightarrow\left(7x-11\right)^3=10^3\)

\(\Rightarrow7x-11=10\)

\(7x=10+11\)

\(7x=21\)

\(x=21:7\)

\(x=3\)

e) \(3^x.3=27\)

\(3^x=27:3\)

\(3^x=9\)

\(\Rightarrow3^x=3^2\)

\(\Rightarrow x=2\)

a) \(2^x-15=17\)

\(\Leftrightarrow2^x=17+15\)

\(\Leftrightarrow2^x=32\)

\(\Leftrightarrow2^x=2^5\)

\(\Leftrightarrow x=5\)

Vậy x = 5

b) \(27.3^x=243\)

\(\Leftrightarrow3^x=243:27\)

\(\Leftrightarrow3^x=9\)

\(\Leftrightarrow3^x=3^2\)

\(\Leftrightarrow x=2\)

Vậy x = 2

c) \(\left(7x-11\right)^3=2^5.5^2+200\)

\(\Leftrightarrow\left(7x-11\right)^3=800+200\)

\(\Leftrightarrow\left(7x-11\right)^3=1000\)

\(\Leftrightarrow\left(7x-11\right)^3=10^3\)

\(\Leftrightarrow7x-11=10\)

\(\Leftrightarrow7x=10+11\)

\(\Leftrightarrow7x=21\)

\(\Leftrightarrow x=21:7\)

\(\Leftrightarrow x=3\)

Vậy x = 3

d) \(3^x.3=27\)

\(\Leftrightarrow3^x=27:3\)

\(\Leftrightarrow3^x=9\)

\(\Leftrightarrow3^x=3^2\)

\(\Leftrightarrow x=2\)

Vậy x = 2

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