Let f (t) give the number of liters of fuel oil burned in t days, and w (r) the liters burned in r weeks. Find a formula for w by scaling the input of f.

7 f (t)

Step-by-step explanation:

So, our f (t) is the number of liters burned in t days. If t is 1, f (t) = f (1) and so on for every t.

w (r) id the number of liters in r weeks. This is, in one week there are w (1) liters burned.

As in one week there are 7 days, we can replace the r, that is a week, by something that represents 7 days. As 1 day is represented by t, one week can be 7t (in other words r = 7t). So, we have that the liters burned in one week are:

w (r) = w[7f (t) ]

So, we represented the liters in one week by it measure of days.

So, we can post that the number of liters burned in 7 days is the same as the number of liters burned 1 day multiplied by 7 times. So:

w (r) = w[7 f (t) ] = 7 f (t)

Here we hace the w function represented in terms of t instead of r.