c) Giải:
\(\frac{1-x}{3}=\frac{27}{1-x}\\ \Leftrightarrow\left(1-x\right)\left(1-x\right)=27.3\\ \Rightarrow\left(1-x\right)^2=81\\ \Rightarrow\left(1-x\right)^2=\pm9^2\\ 1-x=\pm9\)
+) 1-x=9
x=1-9
x=-8
+) 1-x=-9
x=1-(-9)
x=10
Vậy \(x\in\left\{-8;10\right\}\)
Chúc bạn học tốt!
\(\Rightarrow\left(x-1\right)\left(1-x\right)=3.27\)
\(\Rightarrow\left(x-1\right)\left(-1\right)\left(x-1\right)=81\)
\(\Rightarrow\left(x-1\right)^2=-81\)
Mặt khác \(\left(x-1\right)^2\ge0\) với mọi x
=> \(x\in\varnothing\)
\(\frac{1-x}{3}=\frac{27}{1-x}\)
\(\left(1-x\right)^2=27.3=81=\pm9^2\)
*\(1-x=9\Rightarrow x=-8\)
*\(1-x=-9\Rightarrow x=10\)
Vậy x = -8;x=10
\(\frac{1-x}{3}=\frac{27}{1-x}\)
\(\Leftrightarrow\left(1-x\right)\left(1-x\right)=3\cdot27\)
\(\Leftrightarrow\left(1-x\right)^2=81\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}1-x=9\\1-x=-9\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x=-8\\x=10\end{array}\right.\)
Vậy x={-8;10}
\(\frac{1-x}{3}=\frac{27}{1-x}\)
\(\Rightarrow\left(1-x\right)^2=3\cdot27\)
\(\left(1-x\right)^2=81\)
\(\Rightarrow1-x=\pm81\)
Nếu \(1-x=81\)\(x=1-81\)
\(x=-80\)
Nếu \(1-x=-81\)\(x=1-\left(-81\right)\)
\(x=82\)
Vậy \(x=-80\) hoặc \(x=82\)
