Răspuns :
x/(x+3) + 4x/(6-2x) =
= x/(x+3) + 4x/2(3-x) =
= x/(x+3) + 2x/(3-x) =
= x/(x+3) - 2x/(x-3) =
= x(x-3)/(x+3)(x-3) - 2x(x+3)/(x+3)(x-3) =
= (x^2-3x-2x^2-6x)/(x^2-9) =
= (-x^2-9x)/(x^2-9) =
= -x(x+9)/(x^2-9)
= x/(x+3) + 4x/2(3-x) =
= x/(x+3) + 2x/(3-x) =
= x/(x+3) - 2x/(x-3) =
= x(x-3)/(x+3)(x-3) - 2x(x+3)/(x+3)(x-3) =
= (x^2-3x-2x^2-6x)/(x^2-9) =
= (-x^2-9x)/(x^2-9) =
= -x(x+9)/(x^2-9)