Which sentence uses an objective tone?
we will plant the best garden of any school in the area.
the new campus garden will surely be envied by other schools.
a garden would provide numerous benefits to the students.
you will probably agree that gardens have many benefits.

Objective tone is used to provide unbiased, neutral, factual information. Therefore, items written using an objective tone are often impersonal and do not include any opinion or information whatsoever about the writer. Within this list, the sentence that meets with all these requirements and uses an objective tone is: a garden would provide numerous benefits to the students.

Objective tone refers to a style of writing which is impersonal. An objective tone doesn't include the information about the author but about something. For instance,

The dish took 15 minutes to cook.

It is an objective tone

Whereas, a sentence such as:

I took 15 Minutes to cook the dish.

It is a subjective tone as it includes 'I.'

Therefore, sentence which uses an objective tone is:

A garden would provide numerous benefits to the students.

in the problem you wrote said that the taxi charges $0.070 per mile(which would be 7 cents per mile), but then in your suggested equation you have it as $0.70 per mile (which is 70 cents per mile).

the latter seems more realistic, so i will assume that the taxi costs $5.00 and charges $0.70 per mile with tolls costing an additional $3.50. and it asks you to find how far you can travel on $36.50.

let x the number of miles traveled. since the taxi charges $0.70 per mile, multiplying this by the miles traveled (x) will yield the cost of the taxi ride as far as how far it took you. then adding this amount to the cost of the taxi ($5.00) and the additional cost for the tolls ($3.50) will give you the total cost of the taxi ride ($36.50)

that is,

            (0.70)x + 5.00 + 3.50 = 36.50

adding the like terms on the left-hand side of this equation, we arrive at the following:

            (0.70)x + 8.50 = 36.50

subtracting 8.50 from both sides of the equation, we get:

            (0.70)x = 28.00

to solve for x, divide both sides of the equation above by the coefficient of x (that being, 0.70):

            x = 40

thus, you can travel up to 40 miles on $36.50

c. barbarians with unexpected intelligence