5x-4=16. I hope this helps :)
Nonprportional is what I would think
Answer:

Step-by-step explanation:
The given expression can be represented as:.5⁶
Required
Find equivalent expression

Express 6 as 3 + 3

Apply the following law of indices

So, we have:

Express
as 125

Hence, option (b) is equivalent
So you would need to add:
500$ + 80$ + 175$ = 755$
Since John paid 900$ then you would subtract how much he is buying it for from how much Davis spent to fix it
900$ - 755$ = 145$ (on profit Davis earned)