What is the answer I don't know how to solve this ​

He amount of carbon-14 present in animal bones t years after the animal's death is given by p(t)equals=upper p 0 e superscript negative 0.00012097 tp0e−0.00012097t. how old is an ivory tusk that has lost 26% of its carbon-14?

If f(x)= 3x+6 which of the following is the inverse of f(x)

Anyone know? will mark brainliest if you're correct!