3) \(...\Rightarrow2^x\left(2^3+1\right)=36\)

\(\Rightarrow2^x.9=36\)

\(\Rightarrow2^x=4\)

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

4) \(...\Rightarrow4^{x+1}-4^x=12\)

\(\Rightarrow4^x\left(4-1\right)=12\)

\(\Rightarrow4^x.3=12\)

\(\Rightarrow4^x=4=4^1\Rightarrow x=1\)

5) \(...\Rightarrow5^{x+1}\left(5^2-1\right)=3000\)

\(\Rightarrow5^{x+1}.24=3000\)

\(\Rightarrow5^{x+1}=125\)

\(\Rightarrow5^{x+1}=5^3\)

\(\Rightarrow x+1=3\)

\(\Rightarrow x=2\)

6) Bạn xem lại đề

a. \(2^x.2^3+2^x=36\)

\(2^x\left(2^3+1\right)=36\)

\(2^x.9=36\)

\(2^x=4\Rightarrow x=2\)

b. \(4^x.4^1-\left(2^2\right)^x=12\)

\(4^x.4-4^x=12\)

\(4^x\left(4-1\right)=12\)

\(4^x.3=12\)

\(4^x=4\)

x = 1

c. \(5^x.5^3-5^x.5^1=3000\)

\(5^x\left(5^3-5^1\right)=3000\)

\(5^x.120=3000\)

\(5^x=25\)

x = 2

d. \(4^{x+1}=2^{2x}\)

\(4^x.4=\left(2^2\right)^x\)

\(4^x.4=4^x\)

Có vẻ như câu 4 này để bài thiếu 

a) 42 - x = 5

x = 42 - 5

x = 37

b) 15.(x + 4) = 75

x + 4 = 75 : 15

x + 4 = 5

x = 5 - 4

x = 1

d) x + 18 = 12

x = 12 - 18

x = -6

e) 2x - 15 = -19

2x = (-19) + 15

2x = -4

x = -4 : 2

x = -2

f) 36 : (x^3 - 12) = -3

x^3 - 12 = 36 : (-3)

x^3 - 12 = -12

x^3 = 0

=> x = 0

g)x + 15 = 35

x = 35 - 15

x = 20

h) 2x - 13 = 3^2

2x - 13 = 9

2x = 9 + 13

2x = 22

x = 22 : 2

x = 11

a) 42-x=5

         x=42-5

         x= 37

b)15*(x+4)=75

        x+4=75:15

        x+4=5

        x    =5-4

       x     = 1

a) 42 - x = 5

x = 42 - 5

x = 37

b) 15.(x + 4) = 75

x + 4 = 75 : 15

x + 4 = 5

x = 5 - 4

x = 1

d) x + 18 = 12

x = 12 - 18

x = -6

e) 2x - 15 = -19

2x = (-19) + 15

2x = -4

x = -4 : 2

x = -2

f) 36 : (x^3 - 12) = -3

x^3 - 12 = 36 : (-3)

x^3 - 12 = -12

x^3 = 0

=> x = 0

g)x + 15 = 35

x = 35 - 15

x = 20

h) 2x - 13 = 3^2

2x - 13 = 9

2x = 9 + 13

2x = 22

x = 22 : 2

x = 11

Bài 2:

a) 11. x = -55

x = -55 : 11

x = -5

Vậy x = -5

b) -3 . x = -12

x = -12 : (-3)

x = 4

Vậy x = 4

c) 3x - 12 = -48

3x = -48 + 12

3x = -36

x = -36 : 3

x = -12

Vậy x = -12

d) 10 + 23 . (2x - 10) = -36

23 . (2x - 10) = -36 - 10

23 . (2x - 10) = -46

2x - 10 = -46 : 23

2x - 10 = -2

2x = -2 + 10

2x = 8

x = 8: 2

x = 4

Vậy x = 4

f) | 2x - 1| + 3 = 8

|2x - 1| = 8 - 3

|2x - 1| = 5

\(\Rightarrow\left[\begin{matrix}2x-1=5\\2x-1=-5\end{matrix}\right.\Rightarrow\left[\begin{matrix}2x=6\\2x=-4\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=3\\x=-2\end{matrix}\right.\)

Vậy x = 3 hoặc x = -2

g) |2x² - 3| - 4 = 11

|2x²- 3| = 11 + 4

|2x² - 3| = 15

\(\Rightarrow\left[\begin{matrix}2x^2-3=15\\2x^2-3=-15\end{matrix}\right.\Rightarrow\left[\begin{matrix}2x^2=18\\2x^2=-12\end{matrix}\right.\Rightarrow\left[\begin{matrix}x^2=9\\x^2=-6\end{matrix}\right.\Rightarrow\left[\begin{matrix}x^2=3^2\\\left(loại\right)\end{matrix}\right.\Rightarrow\left[\begin{matrix}x=3\\\end{matrix}\right.\)

Vậy x = 3.

Bài 1:

\((-48) . 72 +36 . (-304) \)

\(=\left[\left(-48\right).\left(36.2\right)\right]+36.\left(-340\right)\)

\(=\left[\left(-48\right).2\right].36+36.\left(-340\right)\)

\(=\left(-96\right).36+36.\left(-304\right)\)

\(=36.\left[\left(-96\right)+\left(-304\right)\right]\)

\(=36.\left(-400\right)\)

\(=-14400\)

a.

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

\(\Leftrightarrow2\left(4-3x\right)=10+4\)

\(\Leftrightarrow2\left(4-3x\right)=14\)

\(\Leftrightarrow4-3x=7\)

\(\Leftrightarrow3x=-3\)

\(\Leftrightarrow x=-1\)

b.

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

\(\Leftrightarrow3\left(-x+7\right)=-18+12=-6\)

\(\Leftrightarrow-x+7=-6:3=-2\)

\(\Leftrightarrow x=9\)

c.

\(-45:5.\left(-3-2x\right)=3\)

\(\Leftrightarrow-9.\left(-3-2x\right)=3\)

\(\Leftrightarrow-3-2x=-\dfrac{1}{3}\)

\(\Leftrightarrow2x=-\dfrac{8}{3}\)

\(\Leftrightarrow x=-\dfrac{4}{3}\notin Z\left(loại\right)\)

Câu này em ghi sai đề?

d.

\(3x-28=x+36\)

\(\Leftrightarrow2x=28+36\)

\(\Leftrightarrow2x=64\)

\(\Leftrightarrow x=32\)

e.

\(\left(-12\right)^2.x=56+10.13x\)

\(\Leftrightarrow144x=56+130x\)

\(\Leftrightarrow144x-130x=56\)

\(\Leftrightarrow14x=56\)

\(\Leftrightarrow x=4\)

a: \(2x+36:12=5\cdot3\)

\(\Leftrightarrow2x+3=15\)

hay x=6

`2x + 36 : 12 = 53`

`<=>2x + 3 = 53`

`<=>2x = 50`

`<=> x = 25`

d)

`(5x-24).38=2.311`

`<=> 5x-24 = 311/19`

`<=> x = (311/19 + 24)  :5`

`<=> x = 767/95`

\(a,x-36:18=12-15\\ \Rightarrow x-2=-3\\ \Rightarrow x=-1\\ b,92-\left(17+x\right)=72\\ \Rightarrow17+x=20\\ \Rightarrow x=3\\ c,720:\left[41-\left(2x+5\right)\right]=40\\ \Rightarrow41-\left(2x+5\right)=18\\ \Rightarrow2x+5=23\\ \Rightarrow2x=18\\ \Rightarrow x=9\\ d,\left(x+2\right)^3-23=41\\ \Rightarrow\left(x+2\right)^3=64\\ \Rightarrow\left(x+2\right)^3=4^3\\ \Rightarrow x+2=4\\ \Rightarrow x=2\)

b: =>x+17=20

hay x=3

d: =>x+2=4

hay x=2

A = 1
B = 3
C = 9
D = 2

a) \(-45:5.\left(-3-2x\right)=3\)

\(-9.\left(-3-2x\right)=3\)

\(-3-2x=\left(3:-9\right)\)

\(-3-2x=\dfrac{-1}{3}\)

\(-2x=-3-\dfrac{1}{3}\)

-2x=\(\dfrac{-10}{3}\)

\(x=\dfrac{-10}{3}:-2\)

\(x=\dfrac{5}{3}\)

b) 

3x - 28 = x + 36

<=> 3x - x = 36 + 28

<=> 2x = 64

<=> x = 32

Vậy x = 32

c) 

(-12)2.x = 56 + 10.13.x

144.x = 56 + 130.x

144x – 130 x = 56

14x = 56

x = 56: 14

x = 4

Vậy x = 4

\(a,-45:5\cdot\left(-3-2x\right)=3\\ \Leftrightarrow-9\cdot\left(-3-2x\right)=3\\ \Leftrightarrow-2x-3=-\dfrac{1}{3}\\ \Leftrightarrow2x+3=\dfrac{1}{3}\\ \Leftrightarrow2x=-\dfrac{8}{3}\\ \Leftrightarrow x=-\dfrac{4}{3}\\ b,3x-28=x+36\\ \Leftrightarrow2x=64\\ \Leftrightarrow x=32\\ c,\left(-12\right)^2x=56+10\cdot13x\\ \Leftrightarrow144x=56+130x\\ \Leftrightarrow14x=56\\ \Leftrightarrow x=4\)

1 tính nhanh:

(-48)x72+36x(-340)

=(-48)x72+36x2x(-120)

=(-48)x72+72x(-120)

=72x(-48+-120)

=72x(-168)

=-12096

2 tìm x

a)11.x=-55

x=-55:11

x=-5

Vậy x=-5

b)-3.x=-12

x=(-12):(-3)

x=4

Vậy x=4

c)3x-12=48

3x=48+12

3x=60

x=60:3

x=20

Vậy x=20

d)10+23.(2x-10)=-36

23.(2x-10)=-36-10

23.(2x-10)=-46

2x-10=-46:23

2x-10=-2

2x=-2+10

2x=8

x=8:4

x=2

Vậy x=2

f)|2x-1|+3=8

|2x-1|=8-3

|2x-1|=5

Vậy x=5

TH1: 2x-1=5

2x=5+1

2x=6

x=6:2

x=3

TH2:2x-1=-5

2x=-5+1

2x=-4

x=-4:2

x=-2

Vậy x=3 hoặc -2

g)|2x²-3|-4=11

|2x²-3|=11+4

|2x²-3|=15

TH1: 2x²-3=15

2x²=15+3

2x²=18

x²=18:2

x²=9

x=3;-3

TH2:2x²-3=-15

2x²=-15+3

2x²=-12

x²=-12:2

x²=-6

vì x²>0 =>Trường hợp này là vô lý

Vậy x=3 hoặc -3

CHÚC BẠN HỌC GIỎI !