Bonjour,
1) Calculer :
A = 45 - 7 - 8 + 17 - 0 + 1
A = 45 + 17 + 1 - 7 - 8
A = 63 - 15
A = 48
B = 1 + a + 17 - a + 4b
B = 1 + 17 + a - a + 4b
B = 18 + 4b
C = a^2 + b^2 - ab + ab + 2ab
C = a^2 + 2ab + b^2
C = (a + b)^2
2)développer :
A = (a + b)^2
A = a^2 + 2 * a * b + b^2
A = a^2 + 2ab + b^2
B = (a - b)(a + b)
B = a^2 - b^2 (identité remarquable)
Ou
B = a * a + a * b - b * a - b * b
B = a^2 + ab - ab - b^2
B = a^2 - b^2
