1. Tìm x, biết:

a) \(\frac{4}{x}=\frac{8}{6}\). Ta có: \(\frac{8}{6}=\frac{8:2}{6:2}=\frac{4}{3}\Rightarrow x=3\)

b) \(\frac{3}{x-5}=\frac{4}{x+2}\). Ta có: \(5-2=3\)

\(\Rightarrow x=\left(3.5\right)+\left(4.2\right)+3=15+8+3=26\)

c) \(\frac{x}{-2}=\frac{-8}{x}\Rightarrow x=\left(-8\right):\left(-2\right)=4\)

2. Rút gọn

a) \(\frac{2^4.5^2.11^2.7}{2^3.5^3.7^2.11}\Leftrightarrow\frac{2^3.2^1.5^2.11.11.7}{2^3.5^2.5^1.7.7.11}\Leftrightarrow\frac{2^1.11}{5^1.7}=\frac{22}{35}\)

b) Tương tự

c) Tương tự

\(\frac{4}{x}=\frac{8}{6}\Rightarrow x=\frac{4.6}{8}=3\)

\(\frac{3}{x-5}=\frac{-4}{x+2}\Rightarrow3\left(x+2\right)=-4\left(x-5\right)\)

                                \(\Rightarrow3x+6=-4x+20\)

                                \(\Rightarrow3x+4x=20-6\)

                                \(\Rightarrow7x=14\)

                                \(\Rightarrow x=2\)

\(\frac{x}{-2}=\frac{-8}{x}\Rightarrow x^2=\left(-8\right)\left(-2\right)=16\Rightarrow x=\pm4\)

\(\frac{4}{x}=\frac{8}{6}\)

\(\Rightarrow4\cdot6=x\cdot8\)

\(\Rightarrow x=\frac{4\cdot6}{8}\)

\(\Rightarrow x=3\)

làm ơn giúp mình ,bạn nào làm nhanh đúng mình chọn cho nhanh nha mọi người

nhanh nha mọi người

T.T

Bài làm

2².4⁴.2⁶.2.2=2².2⁸.2⁶.2²=2¹⁸

2.2³.2⁷.2⁴=2¹⁵

3².3=3³=27

3⁴.3³.3=3⁸

3.3⁵.3⁴.3²=3¹²

3.3⁶.3⁷.3⁴=3¹⁸

4.4³=4⁴

4⁵.4.4⁷=4¹³

4.4³.4⁵.4⁶=4¹⁵

5.5⁶=5⁷

5.5⁴=5⁵

5.5².5⁴=5⁷

5.5³.5⁴.5⁶=5¹⁴

5.5⁶.5⁴.5³=5¹⁴

x.x²=x³

x.x³.x⁵=x⁹

a.a⁴=a⁵

a.a².a⁴.a⁵.a⁷=a¹⁹

a.a³.a⁵.a⁶=a¹⁵

a.a⁴.a.a⁵.a⁶.a=a¹⁸

x.x³.x⁴=x⁸

x⁵.x⁴.x.x⁷.x⁶=x²³

7.7²=7³

7.7².7⁴.7⁵=7¹²

7³.7⁵.7⁴.7=7¹³

7².7.7⁶.7⁶.7³=7¹⁸

10.10²=10³

10.100.10³=10⁶

10.100.10⁴.1000=10¹⁰

10².10⁴.100.1000=10¹¹

Tk nha !

1;Ta có\(5.3^x=5.3^4\)

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

\(\Rightarrow x=4\)

2.Ta có \(9.5^x=6.5^6+3.5^6\)

\(\Rightarrow9.5^x=5^6.\left(6+3\right)\)

\(\Rightarrow9.5^x=9.5^6\)

\(\Rightarrow5^x=5^6\)\

\(\Rightarrow x=6\)

3, Ta có \(2.3^{x+2}+4.3^{x+1}=10.3^6\)

\(\Rightarrow3^{x+1}.\left(2.3+4\right)=10.3^6\)

\(\Rightarrow3^{x+1}.10=10.3^6\)

\(\Rightarrow3^{x+1}=3^6\)

\(\Rightarrow x+1=6\)

\(\Rightarrow x=5\)

a) 5.3^x = 5.3⁴

=> 3^x=3⁴

=> x=4

b) 9.5^x=6.5⁶+3.5⁶

=> 9.5^x = (6+3)5⁶

=> 9.5^x=9.5⁶

=> 5^x=5⁶

=> x=6

c) 2.3^x+2 + 4.3^x+1 = 10.3⁶

=> 2.3^x+1.3 + 4.3^x+1 = 10.3⁶ 

=> 6.3^x+1+4.3^x+1=10.3⁶

=> (6+4).3^x+1=10.3⁶

=> 10.3^x+1=10.3⁶

=> 3^x+1=3⁶

=> x+1=6

=> x=5

a) pt => 2x-x=-25+5(chuyển vế đổi dấu) =>x=-20

b)pt=>\(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+...+\frac{1}{2x-1}-\frac{1}{2x+1}\)=\(\frac{2016}{2017}\)

      =>\(1-\frac{1}{2x+1}=\frac{2016}{2017}\)=>\(\frac{2x}{2x+1}=\frac{2016}{2017}\). Nhân chéo => x=1008

a 6/2x+1=2/7

    6/2 x+1= 2/7-1

      6/2 x=-5/7

       x   = -5/21

bài gì mà dài vậy