Question 713968
<pre>
5(y-1)² - 2(y-1) - 3

Substitute the letter u for (y-1)

5u² - 2u - 3

Factor that as 

(u - 1)(5u + 3)

Change the parentheses to brackets:

[u - 1][5u + 3]

Now replace u by (y-1)

[(y-1) - 1][5(y-1) + 3]

[y-1 - 1][5y-5 + 3]

[y-2][5y-2]

Go back to parentheses:

(y-2)(5y-2)

Edwin</pre>