Câu hỏi của Ngọc Anh Nguyễn

Question

Tìm x :

a) 1/3.x^2=1/2.x

b) 3^2x+2= 27^2

Đỗ Nguyễn Phương Thảo · Accepted Answer

a) $\frac{1}{3}x^2=\frac{1}{2}x$

$\Leftrightarrow\frac{1}{3}x^2-\frac{1}{2}x=0$

$\Leftrightarrow x\left(\frac{1}{3}x-\frac{1}{2}\right)=0$

$\Leftrightarrow\left[\begin{matrix}x=0\\frac{1}{3}x-\frac{1}{2}=0\end{matrix}\right.\Leftrightarrow\left[\begin{matrix}x=0\\frac{1}{3}x=\frac{1}{2}\end{matrix}\right.\Leftrightarrow\left[\begin{matrix}x=0\x=\frac{3}{2}\end{matrix}\right.$

Vậy: $x=0;\frac{3}{2}$Câu trả lời: a) $\frac{1}{3}x^2=\frac{1}{2}x$

$\Leftrightarrow\frac{1}{3}x^2-\frac{1}{2}x=0$

$\Leftrightarrow x\left(\frac{1}{3}x-\frac{1}{2}\right)=0$

$\Leftrightarrow\left[\begin{matrix}x=0\\frac{1}{3}x-\frac{1}{2}=0\end{matrix}\right.\Leftrightarrow\left[\begin{matrix}x=0\\frac{1}{3}x=\frac{1}{2}\end{matrix}\right.\Leftrightarrow\left[\begin{matrix}x=0\x=\frac{3}{2}\end{matrix}\right.$

Vậy: $x=0;\frac{3}{2}$

Lê Thị Thùy Dung · Answer

b) 32.2x+2=272

$\Leftrightarrow$32.2x+2=$\left(3^3\right)^2$

$\Leftrightarrow$32.2x+2=36

$\Leftrightarrow$2x+2=36:32

$\Leftrightarrow$2x+2=34

$\Leftrightarrow$2x+2=81

$\Leftrightarrow$2x=79

$\Leftrightarrow$x=$\frac{79}{2}$Câu trả lời: b) 32.2x+2=272