Question

Giải PT:

3x² + 2x - 1 = 0

Answer 1

3x²+ 2x- 1= 0

<=> 3x²+ 3x- x- 1= 0

<=> (3x²+ 3x)- (x+ 1)= 0

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

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

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

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

Vậy pt có 2 nghiệm S={ -1; 1/3}

Answer 2

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

\(\Rightarrow3x^2+3x-x-1=0\)

\(\Rightarrow3x\left(x+1\right)-\left(x+1\right)=0\)

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

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

Vậy x=1/3, x=1

Answer 3

Cho mình xin lỗi: x = -1, x = 1/3

Answer 4

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

bai nay max easy

Answer 5

X²+2X+1+2X²-2=0

<X+1>²+2<X²-1>=0

<X+1>²+2<X-1><X+1>=0

<X+1><X+1+2X-2>=0

<X+1><3X-1>=0 

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