Question

Answer 1

`(x+2)(3-x)=0`

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

\(\Leftrightarrow\left[{}\begin{matrix}x=-2\\x=3\end{matrix}\right.\)

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`(x^2 -9)(3x+5)=0`

`<=>(x-3)(x+3)(3x+5)=0`

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

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

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

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Answer 2

`a)(x+2)(3-x)=0`

`<=>[(x+2=0),(3-x=0):}<=>[(x=-2),(x=3):}`

`b)(x^2-9)(3x+5)=0`

`<=>[(x^2-9=0),(3x+5=0):}`

`<=>[(x=+-3),(x=-5/3):}`