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Limits are a fundamental concept in calculus, which deal with the behavior of functions as they approach a specific point. More formally, the limit of a function at a certain point refers to the value that the function approaches as the input (or 'x' value) gets closer and closer to that point. For example, when you see the expression \( \lim _{x \rightarrow c}f(x) \), it's asking what value the function \(f(x)\) is approaching as \(x\) approaches the value \(c\).

Limits come into play when trying to understand continuous and discontinuous points on a graph, and they are essential for calculating derivatives and integrals later on in calculus. An intuitive notion of a limit is similar to getting closer and closer to a destination, but not necessarily arriving there. This foundational idea is what allows mathematicians and scientists to work with concepts like instantaneous velocity and rates of change.

Evaluating limits is the process of finding the value that a function approaches as the input approaches a certain value. In the provided exercise \( \lim _{x \rightarrow-3}(2x+5) \), the evaluation is straightforward. You simply plug in the value \(-3\) for the \(x\) and calculate the function's output.

This 'direct substitution' is possible here because the function \(2x+5\) is continuous at \(x=-3\) and doesn't have any undefined or problematic points at that value. However, not all limits can be evaluated this effortlessly. When a limit leads to an indeterminate form, such as \(0/0\), or when the function is not continuous at the point, other techniques such as factoring, rationalizing, or the use of limit laws become necessary for finding the limit.

Limit laws are a set of rules that allow us to compute limits more systematically, especially when direct substitution is not possible. Some of these laws include the sum law, product law, quotient law, and the power law. For instance, if you have two functions \(f(x)\) and \(g(x)\) and you know their individual limits as \(x\) approaches a value \(c\), these laws help you to find the limits of \(f(x) + g(x)\), \(f(x) \cdot g(x)\), \(\frac{f(x)}{g(x)}\), and \(f(x)^n\) respectively.

In the context of our given problem, since \(2x+5\) is a simple linear function, you may not actually require complex limit laws. However, understanding these laws becomes critical when dealing with more complex functions or when a function's graph has holes, vertical asymptotes, or is not defined at the value for which we are trying to find the limit. Mastering these laws will make evaluating limits easier and prepare you for tackling tougher calculus problems.