Answer:
f(-1) = 16
Explanation:
"output" and the f(x) setup just means to plug in -1 in place of x and calculate.
For the function f(x) = 12(3/4)ˣ you have to already know that once you put that -1 in place of x that the -1 power only goes to the 3/4, not the 12 and also what to do with a negative exponent.
Exponent rules are just shortcuts. The shortcut to know here is that the -1 exponent will flip the 3/4 over and make it 4/3 (there are math reasons for this, it's not random. But that's how it works)
So now you have
f(-1) = 12(3/4)⁻¹ which becomes
f(-1) = 12(4/3)
Now you need to know how to multiply with fractions. Here you have a whole, big number times a fraction, which is:
"big num×top all over bottom"
So multiply the 12 times the 4 and put it over the 3
f(-1) = 48/3 = 16
(or you can "cancel" the 12 with the 3 and get 4×4, which is 16, so it comes out the same)
[SKIP TO HERE IF YOU DON'T CARE WHY]
f(x) = 12(3/4)ˣ
f(-1) = 12(3/4)⁻¹
f(-1) = 12(4/3)
f(-1) = 16