1.
A = 3/ 7 – ( 6/7 * 21/24) = 3/7 * ( 1 – ( 2* 21/24)) = 3/7 *
( 1- 42/24) = 3/7 ( 24/24 – 42/24)
A = 3/7 * -18/24 =
3/7 *( - 3/4 ) = -9/28
B = (3 + 2/3) / 22/9 = 11/3 * 9/22 = 99/66 = 1 33/66 = 1 ½
2.
C = 25 * 3 * 10^4 / 2 * 10^2 = 75 * 10^2/2 = 75/2 * 10^2
= 37 1/2 * 10^2
D = 3* 10^5 * 4 * 10^-6 / 16* 10-4
D = 12/16 * 10^-1 * 10^4 = ¾ * 10^3
3. E = PGCD (485, 581) calcul par la méthode d’Euclyde
581 = 485 + 96
485 = 96 * 5 + 5
5 = 5* 1 +0 le PGCD
de (485,581) est 1
4.
F = ( 9 x^2 – 30 x + 25) – 8x + 6 x^2 = 15 x^2 – 38x + 25 = x ( 15 x – 38) + 25
G = 6x – 2 x^2 + 15 –
5 x – ( 5x +20 – 3 x^2 -12) = - 2x^2 + 3x^2 + x – 5x + 15 -20 + 12 = x^2 – 4x
+7
= x (x -4) +7
5. f(x) = x^2 -5
a)Image de x= -3 par f(x) = 9 – 5 = 4
b) Image de x= 2/3 par f(x) = 4/9 – 5 = 4/9 – 45/9 = - 41/9
