Question

a, x² - 4x = 0                                                b, (2x + 1)² - 4x (x + 3) = 9

c, x² -12x = -36

Answer 1

\(x\left(x-4\right)=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x-4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=4\end{matrix}\right.\)

\(4x^2+4x+1-4x^2-12x-9=0\)

\(-8x-8=0\Leftrightarrow x=-1\)

\(\left(x-6\right)^2=0\)

\(x-6=0\Leftrightarrow x=6\)

Answer 2

c)\(x^2-12x=-36\)

\(x^2-12x+36=0\)

\(\left(x-6\right)^2=0\)

\(\Rightarrow x-6=0\)

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