Answer:
[tex]99 + 50x = 549[/tex]
Alternatively you can write it as;
[tex]50x - 450 = 0[/tex]
Step-by-step explanation:
One time service fee=$99
Rate of service=$50/hour
let unknown hours=x
Therefore the equation is
[tex]99 + 50x = 549[/tex]
or you can further simplify it to:
[tex]50x - 450 = 0[/tex]
And you can then solve for x to be 9 hours.