
David L. answered 07/02/20
Harvard Graduate
This is just a disguised system of equations function. Remember that f(x) is just a fancy way of writing y. Thus, you have two points here (-2,7) and (2,1). From there, you just create two equations and solve for what you don't know.
7 = -2a+b
1 = 2a+b
This works out nicely, as you can just add the two equations together to solve for b (since -2a and 2a add to 0).
8 = 2b
b = 4
Plug in b into either equation (we'll do the first one):
7 = -2a+4
3 = -2a
3/-2 = a
Thus, the values of a and b are -3/2 and 4 respectively.