Salut !
1) aire = 2(3x+2)(x) + 2(2x+1)(x) + 2(3x+2)(2x+1)
= 6x²+4x + 4x²+2x + 2(6x²+3x+4x+2)
= 6x²+4x²+12²+4x+2x+14x+4
= 22x² + 20x + 4
2) volume = (3x+2)(2x+1)(x)
= (6x²+7x+2)(x)
= 6x³ + 7x² + 2x
3) si x=5 alors
aire = 22(5²) + 20(5) + 4 = 654 cm²
volume = 6(5³) + 7(5²) + 2(5) = 935 cm³
