Sagot :
Bonsoir,
A = 5(10x + 8) = 50x +40
B = 9x(6 - 6x) = 54x -54x²
C = 3(4x + 7) + 4(2x - 9)=
12x +21 +8x -36 =
20x - 15
D = 7x(2x - 5) - X(2x - 5)=
14x² -35x -2x² +5x=
12x² -30x
Exercice 2:
Développe puis réduischaque expression.
E = (2x + 5)(3x + 7)=
6x² +14x +15x +35=
6x² +29x +35
F = (5x + 8)(2x - 7)=
10x² -35x +16x -56 =
1àx² -19x -56
G = (2x - 5)(3x - 2)=
6x² -4x -15x +10=
6x² -19x +10
H = (2 + x)(5x - 4)
10x -8 +5x² -4x=
5x² +6x -8
Exercice 3:
Développe puis réduis chaque expression.
J = (x + 7)(3 - 2x) + (5x - 2)(4x + 1)
3x -2x² +21 -14x + 20x² +5x -8x -2=
18x² -14x +19
K = (5x - 2)(5x - 8) - (3x - 5)(x + 7)
25x² -40x -10x +16 -( 3x² +21x -5x -35)=
25x² -40x -10x +16 - 3x² -21x +5x +35 =
22x² -66x + 51
