A = (7x-8)^2 + (5x+3)(7x-8)
1) A = (7x-8)^2 + (5x+3)(7x-8)
A = (7x-8)(7x-8) + (5x+3)(7x-8)
A = (7x)^2 - 7x * (8) - 8 * 7x + 8^2 + (5x+3)(7x-8)
A = 49x^2 - 56x - 56 x + 64 + (5x+3)(7x-8)
A = 49x^2 - 112x + 64 + (5x+3)(7x-8)
A = 49x^2 - 112x + 64 + 5x * 7x - 5x * 8 + 3 * 7x - 8 * 3
A = 49x^2 - 112x + 64 + 35x^2 - 40x + 21x - 24
A = 49x^2 - 112x + 64 + 35x^2 - 19x - 24
A = 49x^2 + 35x^2 - 112x - 19x + 64 - 24
A = 84x^2 - 131x + 40
2) A = 84x^2 - 131x + 40
A =
Je n'ai pas le temps de faire la suite désolée :(
