Algebraic Expansion/Examples/(x + 1)^3/Proof 2

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Example of Algebraic Expansion

$\paren {x + 1}^3 = x^3 + 3 x^2 + 3 x + 1$


Proof

\(\ds \paren {x + 1}^3\) \(=\) \(\ds \paren {x + 1} \paren {x^2 + 2 x + 1}\) Algebraic Expansion: $\paren {x + 1}^2$
\(\ds \) \(=\) \(\ds x \paren {x^2 + 2 x + 1} + 1 \paren {x^2 + 2 x + 1}\) Distributive Property
\(\ds \) \(=\) \(\ds x^3 + 3 x^2 + 3 x + 1\) Distributive Property

$\blacksquare$


Sources