Answer:
Step-by-step explanation:
in cases where we're not given x = 0, we can use division
[tex]f(x) = a*b^x\\12 = a*b^2\\48 = a*b^4\\\frac{48}{12}=\frac{ab^4}{ab^2} \\4 = b^2\\b = \pm2\\12 = a * (2)^2\\12 = 4a\\a = 3\\so\\f(x) = 3(2)^n \\or\\f(x) = 3(-2)^n\\[/tex]
since we're never given a case where x's parity is odd, we cannot determine the positivity/negativity of the common ratio
