Question

3x²+2x−1=0

tìm x biết 

Answer 1

X=\(\frac{1}{3}\)

Answer 2

3^2+2x-1=0 <=> 3x^2+3x-x-1=0 =>3x(x+1)-(x+1)=0 => (3x-1)(x+1)=0 =>\(\orbr{\begin{cases}x=\frac{1}{3}\\x=1\end{cases}}\)

Answer 3

3x² + 2x - 1 = 0

3x² + 3x - x - 1 = 0 

3x(x + 1) - (x + 1) = 0

(3x - 1)(x + 1) = 0

\(\Rightarrow\orbr{\begin{cases}3x-1=0\\x+1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{1}{3}\\x=-1\end{cases}}\)

Answer 4

\(3\times2+2x-1=0\)

\(6+2x-1=0\)

\(6+2x=0+1\)

\(6+2x=1\)

\(2x=1-6\)

\(2x=-5\)

\(\Rightarrow x=\left(-5\right):2\)

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

Answer 5

\(3x^2+2x-1=0\)

\(3x^2+3x-x-1=0\)

\(3x\left(x+1\right)-\left(x+1\right)=0\)

\(\left(3x-1\right)\left(x+1\right)=0\)

\(\Rightarrow\orbr{\begin{cases}3x-1=0\\x+1=0\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{1}{3}\\x=-1\end{cases}}}\)

vậy x=-1 hoặc x=1/3

Answer 6

          \(3x^2+2x-1=0\)

<=>  \(\left(x-\frac{1}{3}\right)\left(x+1\right)=0\)

<=>\(\orbr{\begin{cases}x-\frac{1}{3}=0\\x+1=0\end{cases}}\)

<=>\(\orbr{\begin{cases}x=\frac{1}{3}\\x=-1\end{cases}}\)

Answer 7

x = 1/3 

1 kích cho tớ thôi mà tớ đang bí quá

Answer 8

\(3x^2+2x-1=0\)

\(3x^2+3x-x-1=0\)

\(3x\left(x+1\right)-\left(x+1\right)=0\)

\(\left(3x-1\right)\left(x-1\right)=0\)

\(\hept{\begin{cases}3x-1=0\\x+1=0\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{1}{3}\\x=-1\end{cases}}\)

Answer 9

\(\orbr{\begin{cases}x=\frac{1}{3}\\x=-1\end{cases}}\)

         Vậy x = -1;\(\frac{1}{3}\)