[tex](x + 1) {}^{2} = x {}^{2} + (x \cdot{1} ) \cdot{2 + 1 {}^{2} } = x {}^{2} + 2x + 1[/tex]
Am folosit formula de calcul prescurtat :
[tex](a {}^{} + b {}^{} ) = a {}^{2} + 2 \cdot{(a \cdot{b}) } + b {}^{2} [/tex]
