Question

4x^2-(x+3)^2=0

Tìm x giúp mk nhanh

Answer 1

<=>(2x)²-(x+3)²=0

<=>(2x-x-3)(2x+x+3)=0

<=>-3x.3(x+1)=-9x.(x+1)=0

=>x=0 hoặc x+1=0

<=>x=-1

Answer 2

4x² - (x+3)² = 0

<=> 4x² - (x²+6x+9) = 0

<=> 4x² - x² - 6x - 9 = 0

<=>3x² - 6x = 9

<=> x(3x-6) = 9

Lập bảng a.b = 9 ra được: x \(\in\){3;-1}

Answer 3

\(4x^2-\left(x+3\right)^2=0\\ \left(2x-x-3\right)\left(2x+x+3\right)=0\\ \left(x-3\right)\left(3x+3\right)=0\\ \left\{{}\begin{matrix}x-3=0\\3x+3=0\end{matrix}\right.\\ \left\{{}\begin{matrix}x=3\\x=-1\end{matrix}\right.\)