The equation below gives the amount \(A\), in dollars, a plumber charges for a job that takes \(h\)
hours. Bob and Todd each hired a plumber. The plumber worked 5 hours longer on Todd's job
than on Bob's job. How much more did the plumber charge Todd than Bob?
$$A=35h+72$$
The expression \(35h\) implies that for every increase in \(h\), the Amount \(A\) would increase by 35.
Therefore, a difference of 5 hours would amount to:
$$35(5)=175$$
We can make up a scenario. For example, let's say Bob's job took 1 hour. Todd's job would therefore take
6 hours.
Todd's charge
$$A=35h+72 \text{ ; } h=6$$
$$A=35(6)+72 $$
$$A=210+72=282 $$
Bob's charge
$$ A=35h+72 \text{ ; } h=1 $$
$$A=35(1)+72 $$
$$A=107 $$
The difference in charge is:
$$ 282-107=175$$