Given:
The side lengths of a triangle are (4.5m - 2.7) centimeters, (9.4m + 4.2) centimeters, and (5.3n +9.7) centimeters.
To find:
The perimeter of the triangle.
Solution:
Perimeter of the triangle is the sum of all side lengths of a triangle.
![Perimeter=(4.5m-2.7)+(9.4m+4.2)+(5.3n+9.7)](https://img.qammunity.org/2021/formulas/mathematics/high-school/38x5yanbwapok5p8eslfneb68q4okevm38.png)
On combining like terms, we get
![Perimeter=(4.5m+9.4m)+5.3n+(4.2-2.7+9.7)](https://img.qammunity.org/2021/formulas/mathematics/high-school/pvcbcginu38f7u40so5a9mdjhzz2adyu69.png)
![Perimeter=13.9m+5.3n+11.2](https://img.qammunity.org/2021/formulas/mathematics/high-school/opnu91e44k07s1ptks2ivq82nsf9htmv9u.png)
The perimeter of the triangle is (13.9m+5.3n+11.2) centimeters.
Therefore, the correct option is b.