Question 838059
"Use function notation to write the equation" means that the answer should be written as 
f(x) =... instead of y=... . 
The function would be of the form {{{f(x)=mx+b}}} with constants
{{{m}}} = slope of the line, and
{{{b}}} = y-intercept of the line
 
The points tell you that
{{{f(2)=6}}} and {{{f(3)=11}}} ,
 
In general,
you can substitute and solve as a system of equations, or
you can calculate the slope, and then decide how to figure out the function from then on.
 
You can calculate the slope as the change in y-coordinates divided by the change in x-coordinates:
{{{m=(11-6)/(3-2)}}} --> {{{m=5/1}}} {{{highlight(m=5)}}}
That was easy.
 
From there, substituting the value for {{{m}}} and the coordinates of one of the points (chose one), lets you find {{{b}}} easily:
{{{system(f(x)=mx+b, m=5,f(2)=6)}}}--> {{{6=5*2+b}}} --> {{{6=10+b}}} --> {{{6-10=b}}} --> {{{highlight(b=-4)}}}
 
Now we have {{{highlight(f(x)=5x-4)}}} .
 
Verification:
It is a good idea to plug in {{{x=2}}} and {{{x=3}}} in there to verify that you get {{{f(2)=6}}} and {{{f(3)=11}}} .