Bài 1: 

a) Ta có: \(x\left(x^2-4\right)=0\)

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

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

Vậy: \(x\in\left\{0;2;-2\right\}\)

b) Ta có: \(\left(2x-3\right)+\left(-3x\right)-\left(x-5\right)=40\)

\(\Leftrightarrow2x-3-3x-x+5=40\)

\(\Leftrightarrow-2x+2=40\)

\(\Leftrightarrow-2x=38\)

hay x=-19

Vậy: x=-19

Bài 2: 

a) Ta có: \(-45\cdot12+34\cdot\left(-45\right)-45\cdot54\)

\(=-45\cdot\left(12+34+54\right)\)

\(=-45\cdot100\)

\(=-4500\)

b) Ta có: \(43\cdot\left(57-33\right)+33\cdot\left(43-57\right)\)

\(=43\cdot57-43\cdot33+43\cdot33-33\cdot57\)

\(=43\cdot57-33\cdot57\)

\(=57\cdot\left(43-33\right)\)

\(=57\cdot10=570\)

1) 

  a) 8.8.8.8.8.8.8.8 = 8⁸

  b) 2.2.2.3.6.6 = 2.2.2.3.2.3.2.3

                        = 2⁵.3³

  c) 3.7.21.21.49 = 3.7.3.7.3.7.7.7

                           = 3^3.7⁵

3) Ta có: 2^x - 1 = 5² + 2.5

               2^x - 1 = 25 + 10

               2^x - 1 = 35

               2^x       = 35 + 1

               2^x       = 36

               2^x       = 2⁵

               x         = 5

Chúc bạn học tốt!

1/

- 8.8.8.8.8.8.8.8 = 8⁸

- 2.2.2.3.6.6 =  2.2.2.3.2.3.2.3 = 2⁵ . 3³

- 10.100.1000 = 10.10.10.10.10.10 =10⁶

- 3.7.21.21.49= 3.7.3.7.3.7.7.7= 3³. 7⁵

a: \(2^6\cdot3^3=\left(2^2\cdot3\right)^3=12^3\)

b: \(6^4\cdot8^3=2^4\cdot3^4\cdot2^9=2^{13}\cdot3^4\)

c: \(16\cdot81=36^2\)

d: \(25^4\cdot2^8=100^4\)

bài 1: 

\(3^2.\frac{1}{243}.81^3.\frac{1}{27}\)

\(=3^2.\frac{1}{3^5}.\left(3^4\right)^3.\frac{1}{3^3}\)

\(=\frac{3^2.3^{^{12}}}{3^5.3^3}=\frac{3^{2+12}}{3^{5+3}}\)

\(=\frac{3^{14}}{3^8}=3^{14-8}\)

= 3⁶ =729

2, (x+1)³= -125

<=> (x+1)³=(-5)³

^{<=> x+1= -5}

^{<=> x= -6}

^{vậy x=-6}