`(5x-3)^2=(4x-7)^2` `⇔(5x-3)^2-(4x-7)^2=0` `⇔(5x-3-4x+7)(5x-3+4x-7)=0` `⇔(x+4)(9x-10)=0` `⇔` \(\left[ \begin{array}{l}x+4=0\\9x-10=0\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}x=-4\\x=\dfrac{10}{9}\end{array} \right.\) Vậy `S={-4;10/9}` Bình luận
`(5x-3)^2=(4x-7)^2`
`⇔(5x-3)^2-(4x-7)^2=0`
`⇔(5x-3-4x+7)(5x-3+4x-7)=0`
`⇔(x+4)(9x-10)=0`
`⇔` \(\left[ \begin{array}{l}x+4=0\\9x-10=0\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x=-4\\x=\dfrac{10}{9}\end{array} \right.\)
Vậy `S={-4;10/9}`