Question

find the perimeter. simplify your answer. 8a - 9, 8a - 9, a + 9, 7a - 9

Explanation:

Step1: Recall perimeter formula

Perimeter of a polygon is the sum of all its side lengths. So we add the lengths of the four sides: \((8a - 9)+(8a - 9)+(7a - 9)+(a + 9)\).

Step2: Combine like terms

First, group the \(a\)-terms and the constant terms:

• For \(a\)-terms: \(8a+8a + 7a+a= (8 + 8+7 + 1)a=24a\)
• For constant terms: \(-9-9 - 9+9=(-9-9-9)+9=-18\)

Step3: Form the simplified expression

Combine the results from the \(a\)-terms and constant terms: \(24a-18\).

Answer:

\(24a - 18\)