Answer:
see explanation
Step-by-step explanation:
Given
L = 2ab + 2bc + 2ac ( subtract 2ab from both sides )
L - 2ab = 2bc + 2ac ← factor out c from each term on the right side
L - 2ab = c(2b + 2a) ← divide both sides by (2b + 2a)
[tex]\frac{L-2ab}{2b+2a}[/tex] = c
Then
c = [tex]\frac{108-2(4)(6)}{2(6)+2(4)}[/tex]
= [tex]\frac{108-48}{12+8}[/tex]
=[tex]\frac{60}{20}[/tex]
= 3