(5x + 1)2 - (5x + 3)(5x - 3) = 0
25x2 + 10x + 1 - (25x2 - 9) = 0
25x2 + 10x + 1 - 25x2 + 9 = 0
10x + 10 = 0
\(\Rightarrow\) 10x = -10
\(\Rightarrow\) x = -1
nhớ tik mik nha
tìm x
(5x + 1)^2 - (5x+3)(5x-3)=0
\(\left(5x+1\right)^2-\left(5x^2-3^2\right)=0\)
\(\Rightarrow\left\{{}\begin{matrix}\left(5x+1\right)^2=0\\\left(5x^2-3^2\right)=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}5x+1=0\\10x^2-9=0\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}5x=-1\\10x^2=9\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=-\dfrac{1}{5}\\x^2=0,9\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}x=-\dfrac{1}{5}\\x=\sqrt{0,9}\end{matrix}\right.\)
chúc bạn học tốt nhé !
(5x + 1)2 - (5x + 3)(5x - 3) = 0
\(\Leftrightarrow\) 25x2 + 10x + 1 - 25x2 + 9 = 0
\(\Leftrightarrow\) 10x + 10 = 0
\(\Leftrightarrow\) 10x = - 10
\(\Leftrightarrow\) x = -1
