Question

 

\(\dfrac{1}{5}\)x\(\left(x-1\right)^2\)-6=14

Answer 1

\(\dfrac{1}{5}.\left(x-1\right)^2-6=14\)

\(\dfrac{1}{5}.\left(x-1\right)^2=20\)

\(\left(x-1\right)^2=20:\dfrac{1}{5}\)

\(\left(x-1\right)^2=100\)

⇒\(\left[{}\begin{matrix}x-1=10\\x-1=-10\end{matrix}\right.\)

⇒\(\left[{}\begin{matrix}x=11\\x=-9\end{matrix}\right.\)

Answer 2

\(\dfrac{1}{5}\).\((x-1)^2 -6=14\)

⇔\(\dfrac{1}{5}\) \((x-1)^2=14+6\)

⇔\(\dfrac{1}{5}\) \((x-1)^2=20\)

⇔ \((x - 1)^2 = 20 : \) \(\dfrac{1}{5}\)

⇔ \((x - 1)^2 = 100\)

⇔ \(\left[ \begin{array}{l}x - 1 = 10\\x - 1 = -1 0\end{array} \right.\)

⇔ \(\left[ \begin{array}{l}x= 11\\x=-9\end{array} \right. \)