Answered

1.Calculer pour x= moins 2: A=2moins5x et B= moins 3 (4xmoins 2)
2.Calculer pour x= moins 4: C=(3+2x) (moins 2x+5) et D= moins 3x exposant 2+2xmoins 5
3.Calculer pour x= Fraction 3 sur 4 E=(3+2x)(moins x+2) et F= moins x exposant 2 + 2x moins 1




Sagot :

MARIECHARLINE
Pour x = -2.
A = 2 - 5 * (-2)
A = 12
B = -3 (4 * (-2) -2)
B = -3 - 10
B = 30

Pour x = -4.
C = (3 + 2 * (-4))(-2 * (-4) +5)
C = -5 * 13
C = -65
D = -3 * (-4)² + 2 * (-4) - 5
D = -48 - 13
D = -61

Pour x = 3/4
E = (3 + 2 * 3/4) (-3/4 + 2)
E = 9/2 * 5/4
E = 45/8
F = (-3/4)² + 2 * 3/4 -1
F = 9/16 + 3/2 - 1
F = 17/16


Voilà !
MAUDMARINE
1)
Pour x = -2.
A = 2 - 5 * (-2)
A = 2 - (-10)
A = 12

B = -3 (4 x (-2) -2)
B = -3 (8 x -2)
B = +3 x - 10
B = 30

2)
Pour x = -4.
C = (3 + 2 x (-4)) (-2 x (-4) +5)
C = (3 - 8) (8 + 5)
C = -5 x 13
C = -65
D = -3 * (-4)² + 2 * (-4) - 5
D = -48 - 13
D = -61

3)
Pour x = 3/4
E = (3 + 2 x 3/4) (-3/4 + 2)
E = (3 + 6/4) (5/4)
E = (12/4 + 6/4) (5/4)
E = (6/2 + 3/2) (5/4)
E = 9/2 x 5/4
E = 45/8

F = (-3/4)² + 2 x 3/4 -1
F = (-3/4)² + 6/4 -1
F = (-3/4)² + 3/2 - 1
F = 9/16 + 3/2 - 1
F = 9/16 + 24/16 - 16/16
F = 24/9 - 16/16
F = 17/16