natural log derivatives?

Question

Find y ' and y ".

y= ln(4 x)/x^7

Answer 1

Derivitive found by chain rule.
y'= (1/x^7) d(ln 4x)/dx + ln 4x d(x-7)/dx
y= 4/([4x]*x^7)- (1/7)*ln(4x)* 1/x-8
= (1/x^-8)[1- (1/7)ln(4x)]