Factorize : p+q2-a-b2+p+q-a+b

Matching exercise

    
Match the items on the right to the items on the left.
Step 1
Step 2
Step 3
Step 4
p+q2-a-b2+p+q-a+b=p+q2-a-b2+p+q-a-b
=p+q+a-bp+q-a-b+p+q-a-b
=p+q+a-bp+q-a+b+p+q-a-b
=p+q-a+bp+q+a-b+1