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
Answer:
-9.4
Step-by-step explanation:
–5.3+(-4.1) =
The signs are alike, so we add and take the sign
5.3+4.1 = 9.4
The sign is negative so we take the negative sign
-9.4
Answer:
see explanation↓
Step-by-step explanation:
(a)


ANSWER: Linear binomial
(b)


ANSWER: Quadratic trinomial
(c)


ANSWER: Linear binomial
(d)


ANSWER: Quadratic trinomial
(e)


ANSWER: Quadratic binomial
Whenever you face the problem that deals with maxima or minima you should keep in mind that minima/maxima of a function is always a point where it's derivative is equal to zero.
To solve your problem we first need to find an equation of net benefits. Net benefits are expressed as a difference between total benefits and total cost. We can denote this function with B(y).
B(y)=b-c
B(y)=100y-18y²
Now that we have a net benefits function we need find it's derivate with respect to y.

Now we must find at which point this function is equal to zero.
0=100-36y
36y=100
y=2.8
Now that we know at which point our function reaches maxima we just plug that number back into our equation for net benefits and we get our answer.
B(2.8)=100(2.8)-18(2.8)²=138.88≈139.
One thing that always helps is to have your function graphed. It will give you a good insight into how your function behaves and allow you to identify minima/maxima points.