For the first one you can use the transformation
s = x^2/a^2
t = y^2/b^2
For the second one take the logarithm of each side and use log proporties (see wikipedia) to get what you want.
Transform the following relationships/functions into linear form and identify the expressions for the x and y variables, the slope and the y-intercept:
a) (x^2/a^2) + (y^2/b^2) = 1
b) K(T) = (kBT/h) exp(∆Sá/R) exp(-∆Há/RT) where kB, h, ∆ Sá, ∆Há and R are constants