This is confusing to me

Shelly bought a house five years ago for $150,000 and obtained an 80% loan. now the home is worth $140,000 and her loan balance has been reduced by $12,000. what is shelly's current equity?

Complete this sentence with the best of choices given

Which of the following functions is graphed above? a. f(x) = 4log(x + 4) b. f(x) = -4log(x + 4) c. f(x) = 4log(-x - 4) d. f(x) = -4log(-x + 4)