Toán ( x – 1 )^2 – 2 . 3 = -2 Giúp mk nha tìm x !! 10/07/2021 By Peyton ( x – 1 )^2 – 2 . 3 = -2 Giúp mk nha tìm x !!
<=> x²-2x+1-6=-2 <=>x²-2x-3=0 <=>x²-3x+x-3=0 <=>x(x-3)+(x-3)=0 <=>(x+1)(x-3)=0 <=>+) x+1=0 <=>x=-1 +)x-3=0 <=>x=3 Trả lời
(x – 1)² – 2 . 3 = -2 ⇒ (x – 1)² – 6 = -2 ⇒ (x – 1)² = -2 + 6 ⇒ (x – 1)² = 4 ⇒ \(\left[ \begin{array}{l}(x-1)²=2²\\(x-1)²=(-2)²\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x-1=2\\x-1=-2\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x=2+1\\x=-2+1\end{array} \right.\) ⇒ \(\left[ \begin{array}{l}x=3\\x=-1\end{array} \right.\) Vậy x ∈ {3; -1} Trả lời
<=> x²-2x+1-6=-2
<=>x²-2x-3=0
<=>x²-3x+x-3=0
<=>x(x-3)+(x-3)=0
<=>(x+1)(x-3)=0
<=>+) x+1=0
<=>x=-1
+)x-3=0
<=>x=3
(x – 1)² – 2 . 3 = -2
⇒ (x – 1)² – 6 = -2
⇒ (x – 1)² = -2 + 6
⇒ (x – 1)² = 4
⇒ \(\left[ \begin{array}{l}(x-1)²=2²\\(x-1)²=(-2)²\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x-1=2\\x-1=-2\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=2+1\\x=-2+1\end{array} \right.\)
⇒ \(\left[ \begin{array}{l}x=3\\x=-1\end{array} \right.\)
Vậy x ∈ {3; -1}