Bonsoir,
20 -4x = 0
20 = 4x
x= 20/4
x = 5
3x+3 =4x-2
3+2 = 4x-3x
5 = x
x= 5
x² +1 = -x 65
x² +x = 65 -1
x²+x = 64
13 = 10-x
x= 10 -13
x= -3
(x+3) * 2 = 2x+6
2x+6 = 2x+6
2x-2x = 6-6
0=0
x= 0
x²-1 = 10x -22
x² -10x = -22+1
x²-10x = -21
