Sagot :
Bonsoir
Réécris les expressions suivantes sans parenthèse puis réduis-les :
A= 7 - (2 - x) + 9 + (x - 5)
A = 7 - 2 + x + 9 + x - 5
A = 2x
B = 15+ (7 – X) - 9 - (x - 17)
B = 15 + 7 - x - 9 - x + 17
B = -2x + 39 - 9
B = -2x + 30
D = 19-a-(4 + x) - (5 + 3x) + (7 - 2x)
D = 19 - a - 4 - x - 5 - 3x + 7 - 2x
D = -6x - a + 26 - 9
D = -6x - a + 17
2.
Même consigne :
B = 3x- (-X2+ 2X-7)
B = 3x + x^2 - 2x + 7
B = x^2 + x + 7
A = 2X + (x-4)
A = 2x + x - 4
A = 3x - 4
D = -X - (-X-4)
D = -x + x + 4
D = 4
C= -2x + (-X-4)
C = -2x - x - 4
C = -3x - 4
Réponse:
Exercice 1:
A= 7 - (2 - x) + 9 + (x - 5)= 7 - 2 + x + 9 + x - 5= 2x
B = 15+ (7 – X) - 9 - (x - 17) = 15 + 7 - x-9 - x + 17= -2x + 39-9 = -2x + 30
D = 19-a-(4 + x) - (5 + 3x) + (7 - 2x) = 19 - a -4 -X-5 - 3x + 7 - 2x = -6x - a + 26 - 9 = -6x - a +17
Exercice 2:
B = 3x- (-X2+ 2X-7) = 3x + x²- 2x + 7 = x²+ x + 7
A = 2X + (x-4) = 2x + x - 4 = 3x - 4
D = -X - (-X-4) = -x + x +4 = 4
C= -2x + (-X-4) = -2x - x -4 = -3x - 4