C3 differentiation help

Need help on this question.

My working out so far. Need help from how to get from penultimate step to final answer.

This is the official answer for this question. I have the working out correct but i dont understand how to get to the final answer.

Use Product Rule, (fg)' = fg' +gf'
The right one is a bit more troublesome, use chain rule once

Original post by GulfstG650ER

Use Product Rule, (fg)' = fg' +gf'
The right one is a bit more troublesome, use chain rule once

i already have though

in the second bottom line, you mixed up the polynomials.
it should be -15x^2 (5x-1)^(-2) divided by ((3x)(5x-1)^(-2)) plus 2(5x-1)

It is much easier to use the quotient rule for this question.

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