Answer:
Leading coefficient is the coefficient of the highest power of x.
is the highest power.
Therefore, leading coefficient = 
Option D
How many hours does he rent it?
Either way, the equation would be 30 + 10x
x is the number of hours he rents the digger.
So for example, if he rented it for say 8 hours
30 + 10(8)
30 + 80
$110
The question asks for the rate of toys per hour.
So we shall divide the total toys assembled by the total hours.
Its a five day week.
The number of hours allotted per day are 8.
So total allotted during the week are 8 × 5 = 40 hours.
Number of toys made during the week are 400.
Hence the number of toys assembled per hour per person
= number of toys / number of hours
= 400 / 40
= 10 toys per hour per person.
The average number of toys assembled per hour per person is 10.