Question

(x-3)(x^2+3x+9)-(3x-17)=x^3-12

Answer 1

\(\left(x-3\right)\left(x^2+3x+9\right)-\left(3x-17\right)=x^3-12\)

\(\Leftrightarrow x^3-27-3x+17=x^3-12\)

\(\Leftrightarrow-10-3x=-12\)

\(\Leftrightarrow3x=2\)

\(\Leftrightarrow x=\dfrac{2}{3}\)

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Answer 2

\((x-3)(x^2+3x+9)-(3x-17)=x^3-12 \)

\(pt\Leftrightarrow x^3-27-3x+17=x^3-12\)

\(\Leftrightarrow x^3-3x-10-x^3+12=0\)

\(\Leftrightarrow2-3x=0\)\(\Leftrightarrow x=\dfrac{2}{3}\)