1/ x^+2x-3 + 18/ x^+2x+2 - 18/ x^+2x+1 = 0 1/x^ +6x=0 | * x^ (1+6x^3)/x^=0 x^ не равен 0 1^3+(2x)^3=0 x^3=( 1/2)^3 x=1/2