Chỗ X.X mình sai phai là X+X mới đúng

2X : X = X

2 = X 

2X + X = 6X 

câu này ko biết chắc sai đề 

2X * X = 10X 

2*X*X=10X

gạch X ở hai vế 

ta có 

2*X=10

X = 10: 2

X= 5

a) (X + X) : X = X

2X : X = X

2 = X

b) (X + X) + X = 6X

3X = 6X

6X - 3X = 0

3X = 0

X = 0

c) (X + X).X = 10X

2X . X = 10X

2X = 10

X = 5 

=x^2.x^8.x^4.x^6.x^10/x^1.x^9.x^3.x^7.x^3=3^5

=x^10.x^10.x^10 / x^10.x^10.x^5=3^5

=x^10/x^5=3^5

=x^5=3^5

x=3

\(x^2.x^4.x^6.x^8.x^{10}:\left(x.x^3.x^5.x^7.x^9\right)=243\)

\(x^{2+4+6+8+10}:x^{1+3+5+7+9}=243\)

\(x^{30}:x^{25}=243\)

\(x^{30-25}=243\)

\(x^5=243\)

\(x^5=3^5\)

\(\Rightarrow x=3\)

Vậy \(x=3\)

x^(1+2+...+10)=2018^55

x^55=2018^55

=> x=2018

x.x^2.x^3. ... . x^10 =2018 ^55

x^(1+2+3+...+10)=2018^55

số số hạng của dãy 1+2+3+...+10 là : (10-1):1+1=10(số)

tổng của dãy 1+2+3+...+10 là : (10+1)×10:2=55

=> x^55=2018^55

=> x = 2018

1.x²⁺¹⁺³=64

 x⁶=64

Ta thấy:2⁶=64

        =>x=6

2.x^2+4+6+8+10/ x^1+3+5+7+9=243

   x³⁰/ x²⁵=243

   x^30-25=243

   x⁵=243

Ta thấy:3⁵=243

          =>x=5

1:

<=>x²⁺³⁺¹=64

<=>x⁶       =64

 =>x          =2

2:<=>x^2+4+6+8+10:x^1+3+5+7+9=243

<=>x³⁰:x²⁵=243

<=>x^30-25=243

<=>x⁵=243

=>x=3

a) Ta có: \(3x-1=0\)

\(\Leftrightarrow3x=1\)

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

Vậy: \(S=\left\{\dfrac{1}{3}\right\}\)

b) Ta có: \(5x-2=x+4\)

\(\Leftrightarrow5x-x=4+2\)

\(\Leftrightarrow4x=6\)

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

Vậy: \(S=\left\{\dfrac{3}{2}\right\}\)

\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+....+\frac{1}{\frac{x\left(x+1\right)}{2}}=1\frac{1993}{1991}\)

\(\Leftrightarrow\left(1\cdot\frac{1}{2}\right)+\left(\frac{1}{3}\cdot\frac{1}{2}\right)+\left(\frac{1}{6}\cdot\frac{1}{2}\right)+....+\left(\frac{1}{\frac{x\left(x+1\right)}{2}}\cdot\frac{1}{2}\right)=1\frac{1993}{1991}\div2\)

\(\Leftrightarrow\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+....+\frac{1}{x\left(x+1\right)}=\frac{1992}{1991}\)

\(\Leftrightarrow\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{x\left(x+1\right)}=\frac{1992}{1991}\)

\(\Leftrightarrow\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{x}-\frac{1}{x+1}\right)=\frac{1992}{1991}\)

\(\Leftrightarrow\frac{1}{x+1}=1-\frac{1992}{1991}\)

\(\Leftrightarrow\frac{1}{x+1}=-\frac{1}{1991}\)

\(\Leftrightarrow x=-1992\)

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 !

\(\frac{1}{1.3}+\frac{1}{3.5}+\frac{1}{5.7}+....+\frac{1}{x.\left(x+2\right)}=\frac{20}{41}\)

\(\Rightarrow\frac{1}{2}.\left(\frac{2}{1.3}+\frac{2}{3.5}+\frac{2}{5.7}+....+\frac{2}{x.\left(x+2\right)}\right)=\frac{20}{41}\)

\(\Rightarrow\frac{1}{2}.\left(1-\frac{1}{3}+\frac{1}{3}-\frac{1}{5}+....+\frac{1}{x}-\frac{1}{x+2}\right)=\frac{20}{41}\)

\(\Rightarrow\frac{1}{2}.\left(1-\frac{1}{x+2}\right)=\frac{20}{41}\)

\(\Rightarrow1-\frac{1}{x+2}=\frac{20}{41}:\frac{1}{2}\)

\(\Rightarrow1-\frac{1}{x+2}=\frac{40}{41}\)

\(\Rightarrow\frac{1}{x+2}=1-\frac{40}{41}=\frac{1}{41}\)

=> x + 2 = 41 

=> x = 39