Calculate the first partial derivative with respect to x and y for the following:

f(x,y)=4xln(3y+5x)

I tried to solve this, but I couldn't get to the answer. According to the answers that were published, they were supposed to look like this:

fx=x+3y2y

fy=x+3y6y+2log(x+3y)

How do they come up with these answers? Can you please show me step by step.

Thank you!