Special cases when we insert a term with one

From the 1^st expression

When b₁=b₃=0

When b₂=2

When b₁=b₃=0 as well as b₂=2

From the 2^nd expression in the same way

When b₁=b₃=0

When b₂=0

When b₁=b₃=0 as well as b₂=0