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\(\frac{x-1}{27}=\frac{-3}{1-x}\)
\(\Rightarrow\frac{x-1}{27}=\frac{3}{x-1}\)
\(\Rightarrow\left(x-1\right)^2=81\)
\(\Rightarrow x-1=\pm9\)
Làm nốt nhassssso
a: \(\Leftrightarrow\left(\dfrac{19}{9}-\dfrac{15}{2135}\cdot\dfrac{4270}{9}\right):x=\dfrac{2}{3}\cdot\dfrac{21}{40}:\dfrac{1}{5}\)
=>-11/9:x=7/4
=>x=-11/9:7/4=-11/9*4/7=-44/63
b: =>(x-1)^2=81
=>x-1=9 hoặc x-1=-9
=>x=-8 hoặc x=10
Ta có :
\(\frac{222}{333}=\frac{2}{3}\)
\(\frac{2121}{4040}=\frac{21}{40}\)
\(\frac{132132}{660660}=\frac{1}{5}\)
=> \(\frac{222}{333}:\frac{2121}{4040}:\frac{132132}{660660}=\frac{400}{63}\)
Thay vế phải vào ta được :
\(\left(2\frac{1}{9}-\frac{15}{2135}:\frac{9}{4270}\right):x=\frac{400}{63}\)
\(\Rightarrow\left(-\frac{11}{9}\right):x=\frac{400}{63}\)
\(\Rightarrow x=-\frac{11}{9}:\frac{400}{63}\)
\(\Rightarrow x=-\frac{77}{400}\)
Ta có:(2\(\dfrac{1}{9}\)-\(\dfrac{15}{2135}\) :\(\dfrac{9}{4270}\)): x= \(\dfrac{222}{333}\): \(\dfrac{2121}{4040}\): \(\dfrac{132132}{660660}\)
Suy ra (\(\dfrac{19}{9}\)-\(\dfrac{15}{2135}\) . \(\dfrac{4270}{9}\)): x= \(\dfrac{2}{3}\). \(\dfrac{40}{21}\) . 5
Suy ra (\(\dfrac{19}{9}\)-\(\dfrac{10}{3}\)): x=\(\dfrac{400}{63}\)
(\(\dfrac{-11}{9}\)):x =\(\dfrac{400}{63}\)
Suy ra x= (\(\dfrac{-11}{9}\)):\(\dfrac{400}{63}\) Vậy x=\(\dfrac{-77}{400}\)
\(a,\frac{1}{2}x+\frac{5}{2}=\frac{7}{2}x-\frac{3}{4}\)
\(\Leftrightarrow\frac{1}{2}x+\frac{5}{2}-\frac{7}{2}x=-\frac{3}{4}\)
\(\Leftrightarrow\frac{1}{2}x-\frac{7}{2}x+\frac{5}{2}=-\frac{3}{4}\)
\(\Leftrightarrow-3x+\frac{5}{2}=-\frac{3}{4}\)
\(\Leftrightarrow-3x=-\frac{13}{4}\)
\(\Leftrightarrow x=-\frac{13}{4}:(-3)=-\frac{13}{4}:\frac{-3}{1}=-\frac{13}{4}\cdot\frac{-1}{3}=\frac{13}{12}\)
\(b,\frac{2}{3}x-\frac{2}{5}=\frac{1}{2}x-\frac{1}{3}\)
\(\Leftrightarrow\frac{2}{3}x-\frac{2}{5}-\frac{1}{2}x=-\frac{1}{3}\)
\(\Leftrightarrow\frac{2}{3}x-\frac{1}{2}x-\frac{2}{5}=-\frac{1}{3}\)
\(\Leftrightarrow\frac{1}{6}x-\frac{2}{5}=-\frac{1}{3}\)
\(\Leftrightarrow\frac{1}{6}x=\frac{1}{15}\)
\(\Leftrightarrow x=\frac{1}{15}:\frac{1}{6}=\frac{1}{15}\cdot6=\frac{6}{15}=\frac{2}{5}\)
\(c,\frac{1}{3}x+\frac{2}{5}(x+1)=0\)
\(\Leftrightarrow\frac{1}{3}x+\frac{2}{5}x+\frac{2}{5}=0\)
\(\Leftrightarrow\frac{11}{15}x=-\frac{2}{5}\)
\(\Leftrightarrow x=-\frac{6}{11}\)
d,e,f Tương tự
Bài 1:
a) x^3 = -27 = (-3)^3
=> x = -3
b) (2x-1)^3 = 8^3
=> 2x-1=8
2x = 9
x = 9/2
c) (2x-3)^2 = 9 = 3^2 = (-3)^2
=> 2x -3 = 3 => 2x = 6 => x = 3
2x - 3 = -3 => 2x = 0 => x = 0
KL:...
Bài 2:
a) \(\frac{2563.25^2}{5^{10}}=\frac{2563.5^4}{5^{10}}=\frac{2563}{5^6}\)
\(\frac{2^8.9^2}{6^4.8^2}=\frac{2^8.3^4}{2^{10}.3^4}=\frac{1}{2^2}=\frac{1}{4}\)
Bài 3:
ta có: (-5) < (-3)
=>(-5)^10 < (-3)^10
Tìm x . biết :
\(a,\frac{2}{5}:\left(-x-\frac{1}{2}\right)=\frac{4}{5}\)
\(\Rightarrow-x-\frac{1}{2}=\frac{2}{5}:\frac{4}{5}\)
\(\Rightarrow-x-\frac{1}{2}=\frac{2}{5}.\frac{5}{4}\)
\(\Rightarrow-x-\frac{1}{2}=\frac{1}{2}\)
\(\Rightarrow-x=\frac{1}{2}+\frac{1}{2}\)
\(\Rightarrow-x=1\)
\(\Rightarrow x=-1\)
Vậy \(x=-1\)
a. \(\frac{2}{5}.\left(-x-\frac{1}{2}\right)=\frac{4}{5}\)
\(\Rightarrow-x-\frac{1}{2}=\frac{2}{5}:\frac{4}{5}\)
\(\Rightarrow-x-\frac{1}{2}=\frac{2}{5}.\frac{5}{4}\)
\(\Rightarrow-x-\frac{1}{2}=\frac{1}{2}\)
\(\Rightarrow-x=\frac{1}{2}+\frac{1}{2}\)
\(\Rightarrow-x=1\)
\(\Rightarrow x=-1\)
(x - 1) (x + 1) - (x + 1) (x + 2) = - 19
<=> x² - 1 - (x² + 3x + 2) = - 19
<=> x² - 1 - x² - 3x - 2 = -19
<=> - 3x = -16
<=> x = 16/3
vậy x = 16/3
(2x - 1) .3 - (x + 3). (-2) = -x +1
<=> (6x - 3) - (-2x - 6 ) = 1 - x
<=> 6x - 3 + 2x + 6 = 1 - x
<=> 8x + 3 = 1 - x
<=> 9x = - 2
<=> x = - 2/9
vậy x = - 2/9