a: \(\Leftrightarrow x\left(x-5\right)\left(x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=5\\x=-5\end{matrix}\right.\)

Bài 1.

a: Ta có: \(\left(x-3\right)\left(x^2+3x+9\right)-x\left(x^2-3\right)=0\)

\(\Leftrightarrow x^3-27-x^3+3x=0\)

\(\Leftrightarrow x=9\)

b: Ta có: \(8x^4+x=0\)

\(\Leftrightarrow x\left(8x^3+1\right)=0\)

\(\Leftrightarrow x\left(2x+1\right)\left(4x^2-2x+1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-\dfrac{1}{2}\end{matrix}\right.\)

Bài 1: 

c: x=4

b: x=2

a) (x - 140) : 7 = 3³ - 2³ . 3

(x - 140) : 7 = 27 - 8 . 3 = 27 - 24 = 3

x - 140 = 3 x 7 = 21

x = 21 + 140 = 161

b) x³ . x² = 2⁸ : 2³

x⁵ = 2⁵

=> x = 2

c) (x + 2) . ( x - 4) = 0

x = -2 hoặc 4

d) 3^x-3 - 3² = 2 . 3² =

3^x-3 - 9 = 2 . 9 = 18

3^x-3 = 18 + 9 = 27

3^x-3 = 3³

=> x - 3 = 3

x = 3 + 3 = 6

2.

a) 9 : ( x + 2 )

9 ⋮ 1 ; 9 ⋮ 3 ; 9 ⋮ 9

=> x = -1 ; 1 ; 7

ai nhanh nhất mk k cho nha ^^

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mk ko biet

a) x = 1; x = - 1 3                 b) x = 2.

c) x = 3; x = -2.                 d) x = -3; x = 0; x = 2.

e: =>-40+3+33+40-x=47

=>36-x=47

=>x=-11

f: =>x(x-3)(11-x)(11+x)=0

hay \(x\in\left\{0;3;11;-11\right\}\)

g: =>-62-38-x+2x=-100

=>x-100=-100

hay x=0

i: =>x-12-2x-31=6

=>-x-43=6

=>x+43=-6

hay x=-49

h: =>(x+1)=0

=>x=-1

f: =>x(x-3)(x+11)(x-11)=0

hay \(x\in\left\{0;3;-11;11\right\}\)