Limit factoring I've the following limit to be calculated. $\lim_{x \to 7} \dfrac{5 - \sqrt{4 + 3x}}{7 - x}$ I'm used to solve this limits from Calculus I text books but I've been struggling without success on this one, how make it non-indeterminable ?

**Hint:** multiply by $$\frac{5+\sqrt{4+3x}}{5+\sqrt{4+3x}}$$ And recall that $(\alpha-\beta)(\alpha+\beta) = \alpha^2 - \beta^2$. This _trick_ is called **multiplying by the conjugate** , and it is a way of getting rid of those roots and the $\frac{0}{0}$ type of indetermination.