Can you simplify the expression of 16+(f+4), and can you explain each step?

Question

Can you please explain the expressio!?

Answer 1

16 +(f+4) =

 

16 + ( 4 + f)  <------ commutative property of addition

 

(16+4) + f <---- associative property of addition

 

20 + f   subsitutition 20 = 16+4

 

= f + 20 <--- commutative property of addition