John was working on factoring, y = 7x² - 6x -1, but got stuck. His work is shown below. Help John finish the problem by explaining to him how to continue the work he has started.
Solution:
y = 7x² - 6x -1
= 7x² - 7x + x - 1
= 7x ( x - 1 ) + 1 ( x - 1 )
= ( x - 1 ) ( 7x + 1 )