X²-2x-3=0 x1+x2=2 U x1*x2=-3⇒x1=-1 U x2=3 x³+x²-9x-9=x²(x+1)-9(x+1)=(x+1)(x²-9)=(x+1)(x-3)(x+3) 1/(x-3)(x+1) +1/(x+3)=12/(x+1)(x-3)(x+3) x≠-1 x≠3 x≠-3 1*(x+3)+1*(x+1)(x-3)=12 x+3+x²-2x-3-12=0 x²-x-12=0 x1+x2=1 U x1*x2=-12 x1=4 U x2=-3 не удов усл ответ х=4
x1+x2=2 U x1*x2=-3⇒x1=-1 U x2=3
x³+x²-9x-9=x²(x+1)-9(x+1)=(x+1)(x²-9)=(x+1)(x-3)(x+3)
1/(x-3)(x+1) +1/(x+3)=12/(x+1)(x-3)(x+3)
x≠-1 x≠3 x≠-3
1*(x+3)+1*(x+1)(x-3)=12
x+3+x²-2x-3-12=0
x²-x-12=0
x1+x2=1 U x1*x2=-12
x1=4 U x2=-3 не удов усл
ответ х=4