CALCUL LITTERAL 1) Je me rappelle

2)

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

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

1001² = ( )² =1000² + 2 x1000x1 + 1² = = ( x +2)² = x ² + 2 x x x 2 + 2² = x ² + 4 x + 4

3)

ab axaaxbbxabxb = a² - ab - ba + b² = a² - 2ab + b² (a - b)² = a² - 2ab + b²

97² = (100 – 3)² = 100 ² - 2 * 100 * 3 + 3² = = ( x - 2)² = x ² - 2 x x x 2 + 2² = x ² - 4 x + 4

4)

*7 = *(-2) = *(-9) = -9

axa axb bxa bxb = a² - ab + ba - b² = a² - b² (a + b)(a-b) = a² - b² = 100² - 2² = = ( x + 2)( x - 2) = x ² - 2² = x ² - 4