Exercises on the Append relation

Solved example:
Solve the equation!
<a,b> ⊕ <c,d> = < ___________ >
Type "a,b,c,d" into the text box to get the correct solution:
Solution: < a,b,c,d >

Now it is your turn:

Solve the equation!

<a,b> ⊕ <d,c> = < >

Solve the equation!

<> ⊕ <d,c> = < >

Solve the equation!

<> ⊕ <> ⊕ <> = < >

Solve the equation!

<> ⊕ <d> ⊕ <> = < >

Solve the equation!

<> ⊕ <> ⊕ <d> = < >

Solve the equation!

<d> ⊕ <> ⊕ <> = < >