\(\left(x-\frac{1}{2}\right)^3=\frac{1}{27}\)  

b.

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10 tháng 7 2016

b, \(\left(x+1\right)^2=1\)

Vì \(1^2=1=>\left(x+1=1\right)\)

=> x=0

câu a không có máy tính nhác làm

a) \(\left(x-\frac{1}{2}\right)^3=\frac{1}{27}\)

\(=>\left(x-\frac{1}{2}\right)^3=\left(\frac{1}{3}\right)^3\)

\(=>x-\frac{1}{2}=\frac{1}{3}\)

\(=>x=\frac{5}{6}\)

b) \(\left(x+1\right)^2=1\)

\(=>\orbr{\begin{cases}x+1=-1\\x+1=1\end{cases}=>\orbr{\begin{cases}x=-2\\x=0\end{cases}}}\)

6 tháng 6 2016

\(\left(x+\frac{1}{5}\right)^2+\frac{17}{25}=\frac{26}{25}\\ \left(x+\frac{1}{5}\right)^2=\frac{26}{25}-\frac{17}{25}\\ \left(x+\frac{1}{5}\right)^2=\frac{9}{25}\\ \left|\left(x+\frac{1}{5}\right)\right|=\frac{3}{5}\)

 TH1:   \(x=\frac{3}{5}-\frac{1}{5}\\ x=\frac{2}{5}\)

TH2: \(\left|\left(x+\frac{1}{5}\right)\right|=-\frac{3}{5}\\ x=-\frac{3}{5}-\frac{1}{5}\\ x=-\frac{4}{5}\)

6 tháng 6 2016

\(a,\left(x+\frac{1}{5}\right)^2+\frac{17}{25}=\frac{26}{25}\)

\(\Rightarrow\left(x+\frac{1}{5}\right)^2=\frac{9}{25}\)

\(\Rightarrow\left(x+\frac{1}{5}\right)^2=\left(\frac{3}{5}\right)^2\)

\(\Rightarrow x+\frac{1}{5}=\frac{3}{5}\)

\(\Rightarrow x=\frac{2}{5}\)

\(b,-1\frac{5}{27}-\left(3x-\frac{7}{9}\right)^3=-\frac{24}{27}\)

\(\Rightarrow-\frac{32}{27}-\left(3x-\frac{7}{9}\right)^3=-\frac{24}{27}\)

\(\Rightarrow\left(3x-\frac{7}{9}\right)^3=-\frac{32}{27}+\frac{24}{27}\)

\(\Rightarrow\left(3x-\frac{7}{9}\right)^3=-\frac{8}{27}\)

\(\Rightarrow\left(3x-\frac{7}{9}\right)^3=\left(-\frac{2}{3}\right)^3\)

\(\Rightarrow3x-\frac{7}{9}=-\frac{2}{3}\)

\(\Rightarrow3x=-\frac{2}{3}+\frac{7}{9}\)

\(\Rightarrow3x=\frac{1}{9}\)

\(\Rightarrow x=\frac{1}{27}\)

\(c,\left(x+\frac{1}{2}\right)\left(\frac{2}{3}-2x\right)=0\)

\(\Rightarrow\) \(\left[\begin{array}{nghiempt}x+\frac{1}{2}=0\\\frac{2}{3}-2x=0\end{array}\right.\)  \(\Rightarrow\)  \(\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\2x=\frac{2}{3}\end{array}\right.\)  \(\Rightarrow\)  \(\left[\begin{array}{nghiempt}x=-\frac{1}{2}\\x=\frac{1}{3}\end{array}\right.\)

25 tháng 8 2018

\(a,\frac{27}{x+1}=\frac{x+1}{3}\)

\(\Leftrightarrow27.3=\left(x+1\right)\left(x+1\right)\)

\(\Leftrightarrow81=\left(x+1\right)^2\)

\(\Rightarrow\orbr{\begin{cases}\left(x+1\right)^2=9^2\\\left(x+1\right)^2=\left(-9\right)^2\end{cases}\Rightarrow\orbr{\begin{cases}x+1=9\\x+1=-9\end{cases}}\Rightarrow\orbr{\begin{cases}x=8\\x=-10\end{cases}}}\)

Vậy \(x\in\left\{8;-10\right\}\)

25 tháng 8 2018

a)\(\frac{27}{x+1}=\frac{x+1}{3}\)

Ta có : 27 . 3 = (x + 1)(x + 1)

=> 81 = (x + 1)2

=> 92 = (x + 1)2

=> \(\orbr{\begin{cases}x+1=9\\x+1=-9\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=8\\x=-10\end{cases}}\)

30 tháng 3 2017

cho vài k đi bà con ơi

24 tháng 6 2020

bạn tự làm đi tính toán thôi mà

12 tháng 7 2017

a) (x-1)+(x-2)+(x-3)+...+(-100)=101

(x+x+x+...+x)-(1+2+3+...+100)=101

=> 100x-5050=101

100x=101+5050

100x=5151

x=5151:100

x=5151/100

2 tháng 6 2019

Bài 1 : \(a,\left|x-3,5\right|=7,5\)

\(\Rightarrow\orbr{\begin{cases}x-3,5=7,5\\x-3,5=-7,5\end{cases}}\Rightarrow\orbr{\begin{cases}x=11\\x=-4\end{cases}}\)

\(b,\left|x+\frac{3}{4}\right|-\frac{1}{2}=0\)

\(\Rightarrow\left|x+\frac{3}{4}\right|=\frac{1}{2}\)

\(\Rightarrow\orbr{\begin{cases}x+\frac{3}{4}=\frac{1}{2}\\x+\frac{3}{4}=-\frac{1}{2}\end{cases}}\Rightarrow\orbr{\begin{cases}x=-\frac{1}{4}\\x=-\frac{5}{4}\end{cases}}\)

2 tháng 6 2019

\(c,3,6-\left|x-0,4\right|=0\)

\(\Rightarrow\left|x-0,4\right|=3,6\)

\(\Rightarrow\orbr{\begin{cases}x-0,4=3,6\\x-0,4=-3,6\end{cases}}\Rightarrow\orbr{\begin{cases}x=4\\x=-3,2\end{cases}}\)

\(d,\left|x-\frac{1}{2}\right|-\frac{1}{3}=1\)

\(\Rightarrow\left|x-\frac{1}{2}\right|=\frac{4}{3}\)

\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{2}=\frac{4}{3}\\x-\frac{1}{2}=-\frac{4}{3}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{11}{6}\\x=-\frac{5}{6}\end{cases}}\)

8 tháng 8 2020

1) \(x-\left|1\frac{1}{6}\right|=\frac{5}{21}\)

\(\Rightarrow x-\frac{5}{21}=\left|1\frac{1}{6}\right|\)

\(\Rightarrow x-\frac{5}{21}=\frac{7}{6}\)

\(\Rightarrow x=\frac{7}{6}+\frac{5}{21}=\frac{49}{42}+\frac{10}{42}=\frac{59}{42}\)

2) \(x+\left|-1\frac{2}{3}\right|=\left|-\frac{3}{4}\right|\)

\(\Rightarrow x+\left|-1\frac{2}{3}\right|=\frac{3}{4}\)

\(\Rightarrow x-\frac{3}{4}=-\left|-1\frac{2}{3}\right|\)

\(\Rightarrow x-\frac{3}{4}=-1\frac{2}{3}\)

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

\(\Rightarrow x=-\frac{5}{3}+\frac{3}{4}=-\frac{11}{12}\)

3) \(\left|x-\frac{1}{3}\right|=\frac{5}{2}\)

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

\(\Rightarrow\left[{}\begin{matrix}x=\frac{5}{2}+\frac{1}{3}=\frac{17}{6}\\x=-\frac{5}{2}+\frac{1}{3}=-\frac{13}{6}\end{matrix}\right.\)

4) \(\left|x+\frac{2}{3}\right|=0\)

\(\Rightarrow x+\frac{2}{3}=0\)

\(\Rightarrow x=0-\frac{2}{3}=-\frac{2}{3}\)

5) \(\left|x+2\right|=\frac{1}{3}-\frac{1}{5}\)

\(\Rightarrow\left|x+2\right|=\frac{2}{15}\)

\(\Rightarrow\left[{}\begin{matrix}x+2=\frac{2}{15}\\x+2=-\frac{2}{15}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\frac{2}{15}-2=-\frac{28}{15}\\x=-\frac{2}{15}-2=-\frac{32}{15}\end{matrix}\right.\)

6) \(\left|x-4\right|=\frac{1}{5}-\left(\frac{1}{2}-\frac{5}{4}\right)\)

\(\Rightarrow\left|x-4\right|=\frac{19}{20}\)

\(\Rightarrow\left[{}\begin{matrix}x-4=\frac{19}{20}\\x-4=-\frac{19}{20}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\frac{19}{20}+4=\frac{99}{20}\\x=-\frac{19}{20}+4=\frac{61}{20}\end{matrix}\right.\)

7) \(\left|x-\frac{5}{4}\right|=-\frac{1}{3}\)

\(\left|x-\frac{5}{4}\right|\ge0\)

=> Không có giá trị x thỏa mãn với điều kiện trên