\(\left(1-x\right)\left(5x+3\right)=\left(3x-7\right)\left(x-1\right)\)

\(< =>\left(1-x\right)\left(5x+3+3x-7\right)=0\)

\(< =>\left(1-x\right)\left(8x-4\right)=0\)

\(< =>\orbr{\begin{cases}1-x=0\\8x-4=0\end{cases}< =>\orbr{\begin{cases}x=1\\x=\frac{1}{2}\end{cases}}}\)

\(\left(x-2\right)\left(x+1\right)=x^2-4\)

\(< =>\left(x-2\right)\left(x+1\right)=\left(x-2\right)\left(x+2\right)\)

\(< =>\left(x-2\right)\left(x+1-x-2\right)=0\)

\(< =>-1\left(x-2\right)=0\)

\(< =>2-x=0< =>x=2\)

\(2x^3+3x^2-32x=48\)

\(< =>x^2\left(2x+3\right)-16\left(2x+3\right)=0\)

\(< =>\left(x^2-16\right)\left(2x+3\right)=0\)

\(< =>\left(x-4\right)\left(x+4\right)\left(2x+3\right)=0\)

\(< =>\hept{\begin{cases}x=4\\x=-4\\x=-\frac{3}{2}\end{cases}}\)

\(2x-49=5.32\\ \Leftrightarrow2x-49=160\\ \Leftrightarrow2x=209\\ \Leftrightarrow x=\dfrac{209}{2}\)

\(200-\left(2x+6\right)=43\\ \Leftrightarrow2x+6=157\\ \Leftrightarrow2x=151\\ \Leftrightarrow x=\dfrac{151}{2}\)

\(135-5\left(x+4\right)=35\\ \Leftrightarrow5\left(x+4\right)=100\\ \Leftrightarrow x+4=20\\ \Leftrightarrow x=16\)

3.5.(x+4)=135-35

       x+4=100:5

       x    =20-4

       x    =16

      c). 135 - 5( x + 4 ) = 35.

135 - 5 . ( x +4) 35

5 . ( x + 4 ) = 135 - 35 = 100

x + 4 = 100 : 5 =20

x = 20 - 4 = 16

a

2x - 49 = 5.9=45

2x=45+49=94

x=94 : 2

x=47

                b). 200 - ( 2x + 6 ) = 43.         

2x + 6 = 200 - 43=157

2x = 157 - 6

2x=151

x=151 : 2

x=

\(7^{2x-6}=49\\ \Rightarrow7^{2x-6}=7^2\\ \Rightarrow2x-6=2\\ \Rightarrow2x=8\\ \Rightarrow x=4\)

7^2x-6 = 49
7^2x-6=72
2x-6=2 
2x=6+2
2x=8
2x=2^3
x=3

 

\(...\Rightarrow\left(2x-6\right)=4^9:4^7\)

\(\Rightarrow2x-6=4^2\)

\(\Rightarrow2x-6=16\)

\(\Rightarrow2x=22\)

\(\Rightarrow x=11\)

(2x-6). 4⁷ = 4⁹

2x-6        = \(\dfrac{4^9}{4^7}\)

2x           = 16+6

x             = \(\dfrac{22}{2}\)

x             = 11

(2x - 6) . 4⁷ = 4⁹

2x - 6 = 4⁹ : 4⁷

2x - 6 = 4²

2x - 6 = 16

2x = 16 + 6

2x = 22

x = 22 : 2

x = 11

(2x-6).4^7 = 4^9

=> 2x-6=4^9 ÷ 4^7

=>2x-6=4^2 = 16

=> 2x = 22

=> x = 11

Sửa đề:

\(7^{2x-6}=49\)

\(7^{2x-6}=7^2\)

\(\Rightarrow2x-6=2\)

\(2x=2+6\)

\(2x=8\)

\(x=8:2\)

\(x=4\)

7^{2x - 6} = 49

7^{2x - 6} = 7² (cùng cơ số)

⇒ 2x - 6 = 2

2x = 2 + 6

2x = 8

x = 8 : 2

x = 4

Rut gon :

2x -6/8-6/56-6/140-6/260=43/52 

                         2x-12/13 =43/52             

                                  2x   =43/52+12/13

                                    x    = 7/4 : 2

                                    x     = 7/8