Solving Limit as x approaches 3 using Multiplication and Division

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SUMMARY

The limit as x approaches 3 for the expression $$\lim_{{x}\to{3}} \frac{\sqrt{6x - 14} - \sqrt{x + 1}}{x -3}$$ can be solved by multiplying both the numerator and denominator by the conjugate $$\sqrt{6x - 14} + \sqrt{x + 1}$$. This technique simplifies the expression, allowing for the cancellation of the factor (x - 3) in the numerator. The discussion confirms that this method effectively resolves the limit without the need for long division.

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I have to solve this limit.

$$\lim_{{x}\to{3}} \frac{\sqrt{6x - 14} - \sqrt{x + 1}}{x -3}$$

Now, I think that by definition x - 3 is a divisor of the numerator, but how do I advance from here? Do I do long division?
 
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tmt said:
I have to solve this limit.

$$\lim_{{x}\to{3}} \frac{\sqrt{6x - 14} - \sqrt{x + 1}}{x -3}$$

Now, I think that by definition x - 3 is a divisor of the numerator, but how do I advance from here? Do I do long division?

How about making the x - 3 in the numerator explicit?
What do you get if you multiply both numerator and denominator by $\sqrt{6x - 14} + \sqrt{x + 1}$?
 
I like Serena said:
How about making the x - 3 in the numerator explicit?
What do you get if you multiply both numerator and denominator by $\sqrt{6x - 14} + \sqrt{x + 1}$?

Okay thanks, now I got it.
 

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