х/(х+3) + (4х+6)/(х^2+4x+3) = 0
x^2 + 4x + 3 = 0
x(1) + x(2) = -4
x(1)*x(2) = 3
x(1) = -1
x(2) = -3
х/(х+3) + (4х+6)/(х+1)(x+3) = 0
x*(x+1)/(x+3)(x+1) + (4x+6)/(x+1)(x+3) = 0
(x^2+x+4x+6)/(x+1)(x+3) = 0
(x^2+5x+6)/(x+1)(x+3) = 0
x^2+5x+6=0
x(1) + x(2) = -5
x(1)*x(2) = 6
x(1) = -3
x(2) = -2
(x+2)(x+3)/(x+1)(x+3) = 0
(x+2)/(x+1)=0
x+1≠0
x≠-1
x+2=0
x=-2
Ответ: -2