Hi,
f ( -3 ) = - 2 and f ( 3 ) = 16 give us Pt(-3,-2) and Pt(3,16)
Finding the slope using difference in the y values/difference in x values
slope = = 18/6 = 3
using the standard slope intercept form of a line
f(x) = 3x + b
Using one of the points(3,16)to solve for b
16 = 9 + b
7 = b
f(x) = 3x + 7