Question

tìm x biết

a. 13x(x-3/7)=0

b. 5x^2-1/3x=0

e. /x.(x+3)/=x

Answer 1

\(a)13x\left(x-\dfrac{3}{7}\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}13x=0\\x-\dfrac{3}{7}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{3}{7}\end{matrix}\right.\)

Vậy \(x\in\left\{0;\dfrac{3}{7}\right\}\)

Answer 2

b: =>x(5x-1/3)=0

=>x=0 hoặc x=1/15

e: =>x^2(x+3)^2=x^2 và x>=0

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