To find the perimeter of the triangle, we need to add the lengths of its three sides.

The three sides are given as:

1. $(7.9a + 8.8b)$ centimeters
2. $(6.2a + 1.5c)$ centimeters
3. $(4.2c + 5.9b)$ centimeters

The perimeter $P$ of the triangle is the sum of the lengths of these sides:

$P = (7.9a + 8.8b) + (6.2a + 1.5c) + (4.2c + 5.9b)$

Now, let's combine the like terms:

• The $a$-terms: $7.9a + 6.2a = 14.1a$
• The $b$-terms: $8.8b + 5.9b = 14.7b$
• The $c$-terms: $1.5c + 4.2c = 5.7c$

Thus, the perimeter expression becomes:

$P = 14.1a + 14.7b + 5.7c$

So, the correct answer is:

$\boxed{5.7c + 14.7b + 14.1a}$

Additional clarifications:

If you'd like more detail about how we combined the terms or how the equation is structured, feel free to ask.

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Here are some follow-up questions to further explore related topics:

1. How do you simplify expressions with multiple variables and constants?
2. What are other methods to calculate the perimeter if we are given different geometric shapes?
3. Can you explain how to handle variables with different exponents in algebraic expressions?
4. What is the role of coefficients when adding terms in algebra?
5. How do you check your work when solving for perimeter in more complex shapes like quadrilaterals?

Tip: Always group similar terms first (variables with their like counterparts) to make simplifying easier!