x -2,-1,0,1,2, and y -5,-2,1,4,7
a. Write out an equation for f(x). Assume the function is linear
If it is linear then the general equation for a straight line
y=mx+c
must apply
Take two sets of coordinates and plug these in
-5=-2m+c
-2=-1m+c
solve for m and c
m=3
c=1
check using another set of points
7=2x3+1 which is fine
so equation is
y=3x+1