Réponse:
a) (1+x) (1+2x) =
1 + x + 2x + 2x² =
2x² + 3x + 1
b) (x²+2) (x-1) =
x³ - x² + 2x - 2 =
c) 2x² (1-3x²) =
2x² - 6x⁴ =
-6x⁴ + 2x²
2)
a) (x+3)(x+5)-4x =
x² + 5x + 3x + 15 - 4x =
x² + 4x + 15
b) x(3-2x) + 5x² + 2x =
3x - 2x² + 5x² + 2x =
3x² + 5x
c) (5-t)(1+2t) + 2(3t+4) =
5 + 10t - t - 2t² + 6t + 8 =
-2t² + 15t + 13
d) 2x²(x+6) - x³ + 4x² - 2x =
2x³ + 12x² - x³ + 4x² - 2x =
x³ + 16x² - 2x