Question

Tìm x:

a. 35x² - 49= 10x²²

 

Answer 1

\(35x^2-49=10x^2< =>25x^2-7^2=0\)

\(< =>\left(5x\right)^2-7^2=0< =>\left(5x+7\right)\left(5x-7\right)=0\)

\(=>\left[{}\begin{matrix}x=-\dfrac{7}{5}\\x=\dfrac{7}{5}\end{matrix}\right.\)

Answer 2

Ta có: \(35x^2-49=10x^2\)

\(\Leftrightarrow25x^2-49=0\)

\(\Leftrightarrow\left(5x-7\right)\left(5x+7\right)=0\)

\(\Leftrightarrow x\in\left\{\dfrac{7}{5};-\dfrac{7}{5}\right\}\)