Réponses

2014-02-26T14:13:32+01:00
A. A1 = (2x - 3)(8x - 4)
A2 = (8x - 4)(x + 5)

b. Aire de A = A1 +  A2 = (2x - 3)(8x -  4) + (8x - 4)(x + 5) = (8x - 4)(2x - 3 + x + 5) = (8x - 4)(3x + 2)

c. Pour x = 6,
A1 = (2 x 6 - 3)(8 x 6 - 4) = (12 - 3)(48 - 4) = 9 x 44 = 396
A2 = (8 x 6 - 4)(6 + 5) = (48 - 4) x 11 = 44 x 11 = 484
A = 396 + 484 = 880