Question

Giải phương trình A) (x-1)²+2=x²+3x B) x-3/x+3 - 2/2-3=-3(x-1)/x²-9 C) 12x+1/12

Answer 1

a) Ta có: \(\left(x-1\right)^2+2=x^2+3x\)

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

\(\Leftrightarrow-5x=-3\)

hay \(x=\dfrac{3}{5}\)

 

Answer 2

câu b sai đề bn

 

Answer 3

câu c tìm gì

Answer 4

ĐKXĐ:\(x\ne\pm3\)

\(\dfrac{x-3}{x+3}-\dfrac{2}{x-3}=\dfrac{-3\left(x-1\right)}{x^2-9}\)

⇔\(\left(x-3\right)\left(x-3\right)-2\left(x+3\right)+3\left(x-1\right)=0\)

⇔\(x^2-3x-3x+9-2x-6+3x-3=0\)

⇔\(x^2-3x=0\)

⇔\(x\left(x-3\right)=0\)

⇔\(\left[{}\begin{matrix}x=0\\x-3=0\end{matrix}\right.\)⇒\(\left[{}\begin{matrix}x=0\\x=3\left(\notinĐKXĐ\right)\end{matrix}\right.\)