\(-\) 1) = 27;...">
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24 tháng 2 2020

a) \(x-1=27\)

\(\Rightarrow x=27+1\)

\(\Rightarrow x=28\)

Vậy \(x=28.\)

b) \(x^2+x=0\)

\(\Rightarrow x.\left(x+1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x+1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=0-1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=-1\end{matrix}\right.\)

Vậy \(x\in\left\{0;-1\right\}.\)

c) \(\left(2x+1\right)^2=25\)

\(\Rightarrow\left(2x+1\right)^2=\left(\pm5\right)^2\)

\(\Rightarrow2x+1=\pm5.\)

\(\Rightarrow\left[{}\begin{matrix}2x+1=5\\2x+1=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=4\\2x=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=4:2\\x=\left(-6\right):2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=-3\end{matrix}\right.\)

Vậy \(x\in\left\{2;-3\right\}.\)

d) \(\left(2x-3\right)^2=36\)

\(\Rightarrow\left(2x-3\right)^2=\left(\pm6\right)^2\)

\(\Rightarrow2x-3=\pm6.\)

\(\Rightarrow\left[{}\begin{matrix}2x-3=6\\2x-3=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=9\\2x=-3\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=9:2\\x=\left(-3\right):2\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{9}{2}\\x=-\frac{3}{2}\end{matrix}\right.\)

Vậy \(x\in\left\{\frac{9}{2};-\frac{3}{2}\right\}.\)

Chúc bạn học tốt!

25 tháng 2 2020

Cảm ơn bạn nhiều nha!!!yeu

16 tháng 11 2017

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

\(\Rightarrow\left[{}\begin{matrix}\left(x-3\right)^2=1^2\\\left(x-3\right)^2=-1^2\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x-3=1\\x-3=-1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=4\\x=2\end{matrix}\right.\)

b) \(\left(x-\dfrac{1}{7}\right)^2=0\)

\(\Rightarrow x-\dfrac{1}{7}=0\)

\(\Rightarrow x=0+\dfrac{1}{7}\)

\(\Rightarrow x=\dfrac{1}{7}\)

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

\(\Rightarrow\left(2x+3\right)^3=\left(-3\right)^3\)

\(\Rightarrow2x+3=-3\)

\(\Rightarrow2x=-6\)

\(\Rightarrow x=-3\)

d) \(-\left(5+35x\right)^2=36\)

\(\Rightarrow\left[{}\begin{matrix}\left(-5-35x\right)^2=6^2\\\left(-5-35x\right)^2=\left(-6\right)^2\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}-5-35x=6\\-5-35x=-6\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}35x=-11\\35x=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=-\dfrac{11}{35}\\x=\dfrac{1}{35}\end{matrix}\right.\)

16 tháng 11 2017

a) (x-3)mũ 2 = 1

Vậy x-3 = 1( vì 1 mũ 2 sẽ bằng 1)

=> x = 1+3 = 4

b) (x - 1/7) mũ 2 = 0

Vậy x - 1/7 = 0 ( vì 0 mũ 2 sẽ bằng 0)

=> x = 0 + 1/7 = 1/7

c) (2x + 3 ) mũ 3 = -27

vậy 2x + 3 = -3 ( vì -3 mũ 3 sẽ bằng -27)

=> 2x = -3-3 = -6

=> x = -6/2 = -3

13 tháng 10 2019

a, (2x - 4)^2 = 36/49

=> 2x - 4 = 6/7 hoặc 2x - 4 = -6/7

=> 2x = 34/7 hoặc x = 22/7

=> x = 34/14 hoặc x = 22/14

b, tương tự a

c, |1 - x| + 0,73 = 3

=> |1 - x| = 2,23

=> 1 - x = 2,23 hoặc 1 - x = -2,23

=> x = -1,23 hoặc x = 3,23

d, tương tự c

16 tháng 10 2019

a) \(\left(2x-4\right)^2=\frac{36}{49}=\frac{6^2}{7^2}=\left(\frac{6}{7}\right)^2\)

\(\Rightarrow2x-4=\frac{6}{7}\Rightarrow2x=\frac{34}{7}\Rightarrow x=\frac{17}{7}\)

b) \(\left(3x-5\right)^2=\frac{36}{25}=\frac{6^2}{5^2}=\left(\frac{6}{5}\right)^2\)

\(\Rightarrow3x-5=\frac{6}{5}\Rightarrow3x=\frac{31}{5}\Rightarrow x=\frac{31}{15}\)

c)\(\left|1-x\right|+0,73=3\Rightarrow\left|1-x\right|=2,27\)

\(\orbr{\begin{cases}TH1.1-x=2,27\Rightarrow x=-1,27\\TH2.1-x=-2,27\Rightarrow x=3,27\end{cases}}\)

Vậy, x=......

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

\(\orbr{\begin{cases}TH1.x+\frac{3}{4}=3\Rightarrow x=\frac{9}{4}\\TH2.x+\frac{3}{4}=-3\Rightarrow x=-3,75\end{cases}}\)

Vậy, x=.......

HOK TỐT

AH
Akai Haruma
Giáo viên
7 tháng 8 2019

a)

\((3x-7)^5=0\Rightarrow 3x-7=0\Rightarrow x=\frac{7}{3}\)

b)

\(\frac{1}{4}-(2x-1)^2=0\)

\(\Leftrightarrow (2x-1)^2=\frac{1}{4}=(\frac{1}{2})^2=(-\frac{1}{2})^2\)

\(\Rightarrow \left[\begin{matrix} 2x-1=\frac{1}{2}\\ 2x-1=\frac{-1}{2}\end{matrix}\right.\Rightarrow \Rightarrow \left[\begin{matrix} x=\frac{3}{4}\\ x=\frac{1}{4}\end{matrix}\right.\)

c)

\(\frac{1}{16}-(5-x)^3=\frac{31}{64}\)

\(\Leftrightarrow (5-x)^3=\frac{1}{16}-\frac{31}{64}=\frac{-27}{64}=(\frac{-3}{4})^3\)

\(\Leftrightarrow 5-x=\frac{-3}{4}\)

\(\Leftrightarrow x=\frac{23}{4}\)

d)

\(2x=(3,8)^3:(-3,8)^2=(3,8)^3:(3,8)^2=3,8\)

\(\Rightarrow x=3,8:2=1,9\)

AH
Akai Haruma
Giáo viên
7 tháng 8 2019

e)

\((\frac{27}{64})^9.x=(\frac{-3}{4})^{32}\)

\(\Leftrightarrow [(\frac{3}{4})^3]^9.x=(\frac{3}{4})^{32}\)

\(\Leftrightarrow (\frac{3}{4})^{27}.x=(\frac{3}{4})^{32}\)

\(\Leftrightarrow x=(\frac{3}{4})^{32}:(\frac{3}{4})^{27}=(\frac{3}{4})^5\)

f)

\(5^{(x+5)(x^2-4)}=1\)

\(\Leftrightarrow (x+5)(x^2-4)=0\)

\(\Leftrightarrow \left[\begin{matrix} x+5=0\\ x^2-4=0\end{matrix}\right.\Leftrightarrow \left[\begin{matrix} x+5=0\\ x^2=4=2^2=(-2)^2\end{matrix}\right.\)

\(\Rightarrow \left[\begin{matrix} x=-5\\ x=\pm 2\end{matrix}\right.\)

g)

\((x-2,5)^2=\frac{4}{9}=(\frac{2}{3})^2=(\frac{-2}{3})^2\)

\(\Rightarrow \left[\begin{matrix} x-2,5=\frac{2}{3}\\ x-2,5=\frac{-2}{3}\end{matrix}\right.\Rightarrow \left[\begin{matrix} x=\frac{19}{6}\\ x=\frac{11}{6}\end{matrix}\right.\)

h)

\((2x+\frac{1}{3})^3=\frac{8}{27}=(\frac{2}{3})^3\)

\(\Rightarrow 2x+\frac{1}{3}=\frac{2}{3}\Rightarrow x=\frac{1}{6}\)

14 tháng 7 2016

a.

\(\left(x-\frac{1}{2}\right)^2=0\)

\(x-\frac{1}{2}=0\)

\(x=\frac{1}{2}\)

b.

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

\(x-2=\pm1\)

TH1:

\(x-2=1\)

\(x=1+2\)

\(x=3\)

TH2:

\(x-2=-1\)

\(x=-1+2\)

\(x=1\)

Vậy x = 3 hoặc x = 1

c.

\(\left(2x-1\right)^3=-8\)

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

\(2x-1=-2\)

\(2x=-2+1\)

\(2x=-1\)

\(x=-\frac{1}{2}\)

d.

\(\left(x+\frac{1}{2}\right)^2=\frac{1}{16}\)

\(\left(x+\frac{1}{2}\right)^2=\left(\pm\frac{1}{4}\right)^2\)

\(x+\frac{1}{2}=\pm\frac{1}{4}\)

TH1:

\(x+\frac{1}{2}=\frac{1}{4}\)

\(x=\frac{1}{4}-\frac{1}{2}\)

\(x=\frac{1}{4}-\frac{2}{4}\)

\(x=-\frac{1}{4}\)

TH2:

\(x+\frac{1}{2}=-\frac{1}{4}\)

\(x=-\frac{1}{4}-\frac{1}{2}\)

\(x=-\frac{1}{4}-\frac{2}{4}\)

\(x=-\frac{3}{4}\)

Vậy \(x=-\frac{1}{4}\) hoặc \(x=-\frac{3}{4}\)

14 tháng 7 2016

HƠI DÀI NHỈucche

18 tháng 9 2017

sao nhiều quá vậy bn chép mỏi tay quá

18 tháng 9 2017

một vài câu cx đc bạn nha

Bài 1: 

a: \(\left(2x-1\right)^4=16\)

=>2x-1=2 hoặc 2x-1=-2

=>2x=3 hoặc 2x=-1

=>x=3/2 hoặc x=-1/2

b: \(\left(2x-y+7\right)^{2012}+\left|x-3\right|^{2013}< =0\)

\(\Leftrightarrow\left\{{}\begin{matrix}2x-y+7=0\\x-3=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=3\\y=2x+7=y=2\cdot3+7=13\end{matrix}\right.\)

c: \(10800=2^4\cdot3^3\cdot5^2\)

mà \(2^{x+2}\cdot3^{x+1}\cdot5^x=10800\)

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

 

a: =>0,2-x=7

=>x=-6,8

b: =>x=6 hoặc x=-6

c: =>x^2=5

hay \(x=\pm\sqrt{5}\)

d: =>x^2=2

hay \(x=\pm\sqrt{2}\)

e: =>x-1=2 hoặc x-1=-2

=>x=-1 hoặc x=3

f: =>2x+1=7 hoặc 2x+1=-7

=>2x=-8 hoặc 2x=6

=>x=3 hoặc x=-4

14 tháng 7 2016

Bài 1 :

a. \(\left|x-\frac{1}{3}\right|< \frac{5}{2}\)

TH1 : nếu \(\left|x-\frac{1}{3}\right|>0\)

\(x-\frac{1}{3}< \frac{5}{3}\)

\(x< 2\)

TH2 : nếu \(\left|x-\frac{1}{3}\right|< 0\)

\(\frac{1}{3}-x< \frac{5}{3}\)

\(x>-\frac{4}{3}\)

14 tháng 7 2016

Bài 2 :

a. \(\left(x-2\right)^2=1\)

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

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

\(\left(x-3\right)\left(x-1\right)=0\)

\(\left[\begin{array}{nghiempt}x-3=0\\x-1=0\end{array}\right.\)

\(\left[\begin{array}{nghiempt}x=3\\x=1\end{array}\right.\)