(2x+3)patrat-2 (x-1)(x+1)+15 =3× (2-x)la patrat-(x+1)la patrat-11
4x patrat+12x+9-2 (x patrat-1)+15=3 (4-4x+x patrat)-(x patrat+2x+1)-11
4x patrat+12x+9-2x patrat+2+15=12-12x+3x patrat-x patrat-2x-1-11
2xpatrat+12x+26=2x patrat-14x
2x patrat+12x-2xpatrat+14x=-26
26x=-26
x=-26÷26
x=-1