Question

x²-8x+15=0

mình cần gấp ạ

Answer 1

https://i.imgur.com/5OGAJSc.jpg

Answer 2

https://socratic.org/questions/how-do-you-solve-x-2-8x-15-0-using-the-quadratic-formula

Answer 3

giải:

\(x^2-8x+15=0\)

\(\Leftrightarrow x^2-5x-3x+15=0\)

\(\Leftrightarrow x\left(x-5\right)-3\left(x-5\right)=0\)

\(\Leftrightarrow\left(x-3\right)\left(x-5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-3=0\\x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=5\end{matrix}\right.\)

Vậy x ∈\(\left\{3;5\right\}\)

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