I've following function which should be linearized:
$$f(x,y)=0.25\left(\ln\left(\dfrac{0.1x+100}{\sqrt{ y+20}}\right)\right)$$
After applying some basic rules, I got this function:
$$0.25\ln(0.1x+100)-0.125\ln(y+20)$$
How do I get rid of the natural logarithm in this function to linearize it?