A = 2/5 +5/12 -1/15 = le dénominateur sera 60
A = 2/5 X 12/12 + 5/12 X 5/5 -1/15 X 4/4
A = 24/ 60 + 25/60 -4/60
A = 49/60 -4/60 = 45/60 = 9/12 = 3/4 Proposition N° 3
B= 8/25 divisé 16/75 = 8/25 X 75/16 = 600/400 = 6/4 = 3/2 Proposition N°2
C= (2x-5)² identité remarquable
C= 4x² -20 x +25 Proposition N°2
D= 49x² -25 = (7x-5)(7x+5) Proposition N° 2
E= (x+3)(x-5) - (x-2)(x+3)
E = (x² -5x +3x -15) - ( x² +3x -2x -6)
E = (x² -2x -15) - (x² +x -6)
E = x² -2x -15 -x² -x +6
E = -3x -9 = -3(x+3) Proposition N° 3
-2 est solution de : (x-2)(2x+4)=0
x-2=0
x = 2
2x+4=0
2x = -4
x = -4/2 = -2 Proposition N°1
Exercice 2.
Développement et réduction
G = (5x-3)² + (+5x-3)(3x +2)
G = ( 25x² -30x +9) + ( 15x² +10x -9x -6)
G = 25x² -30x +9 +15x² +x -6
G = 40x² -29x +3
Factorisation
G = (5x -3)(5x-3) + (5x-3)(3x+2)
G = (5x-3) ( 5x-3 +3x +2)
G = (5x-3) (8x -1)
Equation
(5x-3)(8x-1) = 0
5x-3 = 0
5x = 3
x= 3/5
8x-1=0
8x=1
x= 1/8
3/5 et 1/8 sont les solutions de l'équation.
G pour x = -1
G = (5x-3)² + (+5x-3)(3x +2)
G = (5 X -1 -3)² +(+5X-1 -3)(3X-1 +2)
G = (-5 -3)²+ (-5 -3)(-3 +2)
G = (-8)² + +15 -10 +9 -6
G = + 64 +15 -10 +9 -6
G = +88 - 16
G= +72
