# Confusing $$c$$

Algebra Level 5

$y=\dfrac{x^2+2x+c}{x^2+4x+3c}$

If the set of real values of $$c$$ for which $$y$$ can take all real values for $$x\in \mathbb{R}$$ is in the form $$(a,b)$$, then find $$a+b$$.

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