the given function is $f(x)=b * a^{-x} + c$
the 2 given points are N(1|0) and M(0|2)
What I did so far was inserting the points in the function and solve after c
so I got $c=-\frac{b}{a}$ and $c=b-2$
I don't know how to proceed at this point, can someone explain the next steps?
the given solution from the book is $f(x)=4*2^{-x}-2$
thanks!