#### Answer

$\lim\limits_{x \to 1-}$ f(x) = 3 means the limit of f(x), as x approaches 1 from the left, equals 3. $\lim\limits_{x \to 1+}$ = 7 means the limit of f(x), as x approaches 1 from the right, equals 7.
In this situation, $\lim\limits_{x \to 1}$ f(x) doesn't exist because the value of $\lim\limits_{x \to 1-}$ f(x) $\ne$ the value of $\lim\limits_{x \to 1+}$ f(x) (3 $\ne$ 7)

#### Work Step by Step

Box number 3 in One - sided limits section.