What is the slope of the line that contains the points in the table

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

One line passes through (-7,-4) and (5,4) . another line passes through the point (-4,6) and (6,-9)