Reason:
Factor out 6 so that the 6x becomes simply x. We can think of it as 1x.
When factoring out the 6, we have to divide the 7 by 6.
Notice that distributing the outer 6 back through to each term gets us
6(x+7/6) = 6(x) + 6(7/6) = 6x+7
to help confirm the correct factorization.
