Exercice 3:
[tex]a = (3 + x) {}^{2} \\ a = 3 { }^{2} + 2 \times 3 \times x + x {}^{2} \\ a = 9 + 6x + x {}^{2} \\ \\ b = (x + 5) {}^{2} \\ b = x {}^{2} + 2 \times 5 \times x + 5 {}^{2} \\ b = x {}^{2} + 10x + 25 \\ \\ c = (2x + 1) {}^{2} \\ c = 2x {}^{2} + 2 \times 2x \times 1 + 1 {}^{2} \\ c = 4x {}^{2} + 4x + 1 \\ \\ d = ( - 1 + 3x) {}^{2} \\ d= ( - 1) {}^{2} + 2( - 1) \times (3x) + 3x {}^{2} \\ d = 1 - 6x + 9x {}^{2} \\ \\ e = ( - 3x + 2) {}^{2} \\ e = ( - 3x) {}^{2} + 2( - 3x) \times (2) + 2 {}^{2} \\ e = 9x {}^{2} - 12x + 4[/tex]
Voilà pour l'exercice 3
