Question

a triangle has side lengths of (7m - 2) centimeters, (9m - 5) centimeters, and (6n - 1) centimeters. which expression represents the perimeter, in centimeters, of the triangle?
answer
attempt 1 out of 2
5n - 7 + 16m
9m + 5n
5m + 5n + 4
16m + 6n - 8

Explanation:

Step1: Recall perimeter formula

The perimeter $P$ of a triangle is the sum of the lengths of its sides. So $P=(7m - 2)+(9m - 5)+(6n - 1)$.

Step2: Remove parentheses

$P = 7m-2 + 9m-5+6n - 1$.

Step3: Combine like - terms

Combine the $m$ terms: $7m+9m = 16m$. Combine the constant terms: $-2-5 - 1=-8$. The $n$ term remains as $6n$. So $P=16m + 6n-8$.

Answer:

D. $16m + 6n - 8$