Développer et réduire (x – 5)(x + 1) = (3 + x) x =
Calcul 1 (3x – 1) x =
Calcul 2 (x – 1)(x + 5) =
Calcul 3 (-x – 7) x =
Calcul 4 (x – 3)(x – 5) =
Calcul 5 (x – 5)(x + 5) =
Prêt pour la correction…
Calcul 1 (3x – 1) x
Calcul 1 (3x – 1) x = 3x x x – 1 x x
Calcul 1 (3x – 1) x = 3x x x – 1 x x = 3x² – x
Calcul 2 (x – 1)(x + 5)
Calcul 2 (x – 1)(x + 5) = x x x + x x 5 – 1 x x – 1 x 5
(x – 1)(x + 5) = x x x + x x 5 – 1 x x – 1 x 5 = x² + 5x – x – 5 Calcul 2 (x – 1)(x + 5) = x x x + x x 5 – 1 x x – 1 x 5 = x² + 5x – x – 5
(x – 1)(x + 5) = x x x + x x 5 – 1 x x – 1 x 5 = x² + 5x – x – 5 Calcul 2 (x – 1)(x + 5) = x x x + x x 5 – 1 x x – 1 x 5 = x² + 5x – x – 5 = x² + 4x – 5
Calcul 3 (-x – 7) x
Calcul 3 (-x – 7) x = -x x x – 7 x x
Calcul 3 (-x – 7) x = -x x x – 7 x x = -x² – 7x
Calcul 4 (x – 3)(x - 5)
Calcul 4 (x – 3)(x - 5) = x x x – x x 5 – 3 x x + 3 x 5
(x – 3)(x - 5) = x x x – x x 5 – 3 x x + 3 x 5 = x² – 5x – 3x + 15 Calcul 4 (x – 3)(x - 5) = x x x – x x 5 – 3 x x + 3 x 5 = x² – 5x – 3x + 15
(x – 3)(x - 5) = x x x – x x 5 – 3 x x + 3 x 5 = x² – 5x – 3x + 15 Calcul 4 (x – 3)(x - 5) = x x x – x x 5 – 3 x x + 3 x 5 = x² – 5x – 3x + 15 = x² – 8x + 15
Calcul 5 (x – 5)(x + 5)
Calcul 5 (x – 5)(x + 5) = x x x + x x 5 – 5 x x – 5 x 5
(x – 5)(x + 5) = x x x + x x 5 – 5 x x – 5 x 5 = x² + 5x – 5x – 25 Calcul 5 (x – 5)(x + 5) = x x x + x x 5 – 5 x x – 5 x 5 = x² + 5x – 5x – 25
(x – 5)(x + 5) = x x x + x x 5 – 5 x x – 5 x 5 = x² + 5x – 5x – 25 Calcul 5 (x – 5)(x + 5) = x x x + x x 5 – 5 x x – 5 x 5 = x² + 5x – 5x – 25 = x² – 25
1. 3x² – x 2. x² + 4x – 5 3. -x² – 7x 4. x² – 8x + 15 5. x² – 25