Bonjour,
Résoudre:
1) 2-x²+x= 4-(x²+6x+9)
-x²+x+2= 4-x²-6x-9
-x²+x+x²+6x= -5-2
7x= -7
x= -7/7
x= -1
S= { -1 }
2) 2x-3x²+10-15x= 3(x²-4x+4)-x
-3x²-13x+10= 3x²-12x+12-x
-3x²-13x-3x²+12x+x= 12-10
-6x²= 2
x²= -2/6
x²= -1/3 n'admet aucune solution.
3) 25x²-20x+4-(7x+2-7x²-2x)= 2(16x²-24x+9)+76
25x²-20x+4+7x²-5x-2= 32x²-48x+18+76
32x²-25x+2= 32x²-48x+94
32x²-32x²-25x+48x= 94-2
23x= 92
x= 92/23
x= 4
S= { 4 }
4) [ 12(x+6)-11x)/ 60 ]= [2 (60)-5(8x-15)] / 60
(12x+72-11x)= (120-40x+75)
x+72 = -40x+ 195
x+40x= 195-72
41x= 123
x= 123/41
x= 3
S= { 3 }
5) 417/2 - (4x²-4x/2 +x - 1/2)= 5x/3 - (4x²-28x+49)
417/2-4x²+2x-x+1/2= 5x/3 - 4x²+28x-49
-4x²+4x²+x-28x-5x/3= -49- 417/2 - 1/2
3(- 27x)/3 - 5x/3= -49- 417/2 - 1/2
-86x/3= -258
-86x= 3(-258)
x= -774/-86
x= 9
S= { 9 }
6) x+91-4(3x)-5(x-1)= 0
x+91-12x-5x+5= 0
-16x= -96
x= -96/-16
x= 6
S= { 6 }
