N = original number of comic books
N/2 = number of comic books after he sold half of his collection
N/2 + 16 = number of comic books after he bought 16 more
N/2 + 16 = 36
Solving for N:
![(N)/(2)+16\text{ = 36}\Longrightarrow(N)/(2)=36-16\text{ = 20 }\Longrightarrow(N)/(2)=20\Longrightarrow N\text{ = 20 }\cdot\text{ 2=40}\Longrightarrow\text{ N = 40}](https://img.qammunity.org/2023/formulas/mathematics/college/vil79qvdkcmxusfpi8f8ixyqtimr40bh7l.png)
Answers:
He began with 40 comic books
Equation to represent the problem: N/2 + 16 = 36