сократите дробь х3-3х2-4х+12/(х-3)(х+2)
х3-3х2-4х+12/(х-3)(х+2)=x2(x-3)-4(x-3)/(х+2)(x-3)=(x2-4)(x-3)/(х+2)(x-3)=(x-2)(x+2)/x+2=x-2