Answer:

Step-by-step explanation:
The picture of the question in the attached figure
we know that
In the right triangle of the figure
----> by SOH (opposite side divided by the hypotenuse)
using a calculator

B) f(x) = 3
It’s because all the y values are 3
The equation looks like this:
26=x*3.5+8.50
where x is the number of pen you bought.
We solve it like this:
first, we subtract 8.50 from both sides:
17.50 =3.5*x
now we divide both sides by 3.5:
5=x
so you purchased 5 pens.
So the unit rate would just be the numbers all added up