3. CALCUL LITTERAL 1) Je me rappelle

4. 2)

5. Aire de ABCD = Aire de AEFG = Aire de FHCJ = Aire de EBHF = Aire de GFJD = (a+b)² a² b² ab (a+b)² = a² + b² + ab + ab = a² + b² + 2ab

7. ab axa axb bxa bxb = a² + ab + ba + b² = a² + 2ab + b² (a+b)² = a² + 2ab + b²

8. 1001² = (1000 + 1)² =1000² + 2 x1000x1 + 1² = 1 000 000 + 2 000 + 1 = 1 002 001 ( x +2)² = x ² + 2 x x x 2 + 2² = x ² + 4 x + 4

9. 3)

10. 49 28425 81 19812144 9 -241649 ab axaaxbbxabxb = a² - ab - ba + b² = a² - 2ab + b² (a - b)² = a² - 2ab + b²

11. 97² = (100 – 3)² = 100 ² - 2 * 100 * 3 + 3² = 10 000 - 600 + 9 = 9 409 ( x - 2)² = x ² - 2 x x x 2 + 2² = x ² - 4 x + 4

12. 4)

13. 100 9 91 13*7 = 91 49 81 -32 16*(-2) = -32 16 25 -9 1*(-9) = -9

15. axa axb bxa bxb = a² - ab + ba - b² = a² - b² (a + b)(a-b) = a² - b² = 100² - 2² = 10 000 - 4 = 9 996 ( x + 2)( x - 2) = x ² - 2² = x ² - 4