K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

K viết đề nha!

\(\left(x-1\right)^3\)= 125

=> x - 1 = 5

=> x = 6

Hội con 🐄 chúc bạn học tốt!!!

18 tháng 8 2019

(x - 1)(x - 1)(x - 1) = 125

(x - 1)3 = 125

(x - 1)3 = 53

x - 1 = 5

x = 5 + 1

x = 6

15 tháng 1 2017

vì 5^3 = 125 

=> 1/125 - 1/125 = 0 

=> (1/125-1^3)x(1/125-2^3)x...0x...x(1/125-25^3=0

22 tháng 6 2018

( 1+3+5+7+…+2003+2005) x (125 125 x 127 – 127 127 x 125)

= ( 1+3+5+7+…+2003+2005) x (125 x 1001 x 127 – 127 x 1001x 125)

=  ( 1+3+5+7+…+2003+2005) x                   0  =    0

16 tháng 10 2019

a)\(\left(2x+1\right)^3=5^3\)

\(\Rightarrow2x+1=5\)

\(2x=5-1\)

\(2x=4\)

\(x=4:2\)

\(x=2\)

\(b,\left(2x-1\right)^3=125\)

\(\Rightarrow2x-1=5\)

\(2x=5+1\)

\(2x=6\)

\(x=6:2=3\)

16 tháng 10 2019

b) \(\left(2x-1\right)^3=125\)

\(\left(2x-1\right)^3=5^3\)

\(2x-1=5\)

\(2x=5+1\)

\(2x=6\)

\(x=6:2\)

\(x=3\)

x^3-1=(x-1)(x^2+x+1)

8x^3+1=(2x+1)(4x^2-2x+1)

x^3+1=(x+1)(x^2-x+1)

125-x^3=(5-x)(25+5x+x^2)

x^3+8y^3=x^3+(2y)^3

=(x+2y)(x^2-2xy+4y^2)

64y^3-125x^3

=(4y)^3-(5x)^3

=(4y-5x)(16y^2+20xy+25x^2)

\(27x^3-\dfrac{1}{8}=\left(3x\right)^3-\left(\dfrac{1}{2}\right)^3=\left(3x-\dfrac{1}{2}\right)\left(9x^2+\dfrac{3}{2}x+\dfrac{1}{4}\right)\)

\(a^6-b^3=\left(a^2\right)^3-b^3\)

\(=\left(a^2-b\right)\cdot\left(a^4+a^2b+b^2\right)\)

11 tháng 7 2023

\(26\cdot5^{x-1}-5^{x-1}=125\)

\(\Rightarrow5^{^{x-1}}\cdot\left(26-1\right)=125\)

\(\Rightarrow5^{x-1}\cdot25=125\)

\(\Rightarrow5^{x-1}=\dfrac{125}{25}\)

\(\Rightarrow5^{x-1}=5\)

\(\Rightarrow x-1=1\)

\(\Rightarrow x=1+1\)

\(\Rightarrow x=2\)

\(\Leftrightarrow5^{x-1}\cdot\left(26-1\right)=125\)

=>\(5^{x-1}=5\)

=>x-1=1

=>x=2

17 tháng 3 2022

    = ( 125 x 0,75 + 125 x 25% ) x ( 9 x 11 - 0,9 x 100 - 0,9 x10 )
    = ( 125 x 0,75 + 125 x 0,25 ) x ( 9 x 11 - 9 x 10 - 9 x 1 )
    = 125 x ( 0,75 + 0,25 ) x ( 9 x 11 - 9 x 10 - 9 x 1 )
    =  125 x 9 x ( 11-10 -1 )
    =    125 x 9 x 0
    =        0

b) Ta có: \(-5+\left|3x-1\right|+6=\left|-4\right|\)

\(\Leftrightarrow\left|3x+1\right|+1=4\)

\(\Leftrightarrow\left|3x+1\right|=3\)

\(\Leftrightarrow\left[{}\begin{matrix}3x+1=3\\3x+1=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}3x=2\\3x=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}\\x=-\dfrac{4}{3}\end{matrix}\right.\)

Vậy: \(x\in\left\{\dfrac{2}{3};-\dfrac{4}{3}\right\}\)

c) Ta có: \(\left(x-1\right)^2=\left(x-1\right)^4\)

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

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

\(\Leftrightarrow\left(x-1\right)^2\cdot\left[\left(x-1\right)^2-1\right]=0\)

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

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

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

Vậy: \(x\in\left\{0;1;2\right\}\)

d) Ta có: \(5^{-1}\cdot25^x=125\)

\(\Leftrightarrow5^{-1}\cdot5^{2x}=5^3\)

\(\Leftrightarrow5^{2x-1}=5^3\)

\(\Leftrightarrow2x-1=3\)

\(\Leftrightarrow2x=4\)

hay x=2

Vậy: x=2

 

16 tháng 2 2021

cảm ơn nhìu ak

 

`@` `\text {Ans}`

`\downarrow`

`a)`

\(5\cdot x^3-5=0\)

`=> 5*x^3 = 0+5`

`=> 5*x^3 = 5`

`=> x^3 = 5 \div 5`

`=> x^3 = 1`

`=> x^3 = 1^3`

`=> x=1`

Vậy, `x=1.`

`b)`

\(( x+1)^2 = 16\)

`=> (x+1)^2 = (+-4)^2`

`=>`\(\left[{}\begin{matrix}x+1=4\\x+1=-4\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=4-1\\x=-4-1\end{matrix}\right.\)

`=>`\(\left[{}\begin{matrix}x=3\\x=-5\end{matrix}\right.\)

Vậy, `x \in {3; -5}`

`c)`

\(( x+1)^3 = 27\)

`=> (x+1)^3 = 3^3`

`=> x+1=3`

`=> x=3-1`

`=> x=2`

Vậy, `x=2.`

`d)`

\(( x-1)^3 = 343\)

`=> (x-1)^3 = 7^3`

`=> x-1=7`

`=> x=7+1`

`=> x=8`

Vậy, `x=8.`

`e)`

\((2x - 1^3) = 125\) hay đề là `(2x-1)^3 = 125` vậy ạ?

Mình làm cả 2 TH nhé!

`(2x-1^3)=125`

`=> 2x-1=125`

`=> 2x=125+1`

`=> 2x=126`

`=> x=126 \div 2`

`=> x=63`

TH2:

`(2x-1)^3 = 125`

`=> (2x-1)^3 = 5^3`

`=> 2x-1=5`

`=> 2x=5+1`

`=> 2x=6`

`=> x=6 \div 2`

`=> x=3`

Vậy, `x=3.`

26 tháng 6 2023

(a) \(5x^3-5=0\Leftrightarrow5x^3=5\Leftrightarrow x^3=1\Leftrightarrow x=1\)

(b) \(\left(x+1\right)^2=16\Rightarrow\left[{}\begin{matrix}x+1=4\\x+1=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-5\end{matrix}\right.\)

(c) \(\left(x+1\right)^3=27\Leftrightarrow x+1=3\Leftrightarrow x=2\)

(d) \(\left(x-1\right)^3=343\Leftrightarrow x-1=7\Leftrightarrow x=8\)

(e) \(\left(2x-1\right)^3=125\Leftrightarrow2x-1=5\Leftrightarrow2x=6\Leftrightarrow x=3\)