how do we do this and is this edexcel spec

[slender locust]

By substitution

What i would do is first factor out that 9/5 and then let u = 2x-4

du/dx = 2 so dx = 1/2 du

Hence

$$\frac{9}{5}\int {\frac{1}{2x-4}dx} = \frac{9}{10}\int {\frac{1}{u}du} = \frac{9}{10}ln|u|+c = \frac{9}{10}ln|2x-4|+c$$

[maiden ridge]

Arizus