5+3.2n-6-4.8n
5 + 3.2n - 6 - 4.8n
= 5 + 3.2n + -6 + -4.8n
We can add numbers in any order.
= 5 + -6 + 3.2n + -4.8n
= (5 + -6) + (3.2n + -4.8n)
= (5 - 6) + (3.2n - 4.8n)
= ( -1 ) + ( -1.6n )
= -1 - 1.6n