a2(a+1)-2a(a+1)+a+1

Put parentheses around the last two terms

a2(a+1)-2a(a+1)+(a+1)

Put a 1 in front of the last parentheses:

a2(a+1)-2a(a+1)+1(a+1)

Now you see that each term contains a (a+1)

a2(a+1)-2a(a+1)+1(a+1)

And you can factor out the red (a+1).

(a+1)(a2-2a+1)

Next, the black part factors:

(a+1)(a-1)(a-1)

or

(a+1)(a-1)2

or dropping the red coloring:

(a+1)(a-1)2

becomes



Edwin