Kono kagi de machigai arimasen.

There is no mistake, this is the correct key.

Sono koe wa, kare no mono ni machigainakatta.

That voice was undoubtedly his.

Kono sankousho o shikkari benkyou sureba, goukaku wa machigainai.

If you study this reference book thoroughly, passing is guaranteed.

Kore wa shinrai dekiru yuujin kara eta, machigainai jouhou desu.

This is reliable information obtained from a trustworthy friend.

Kono resutoran no ryouri wa dore o tabete mo oishii kara, erande machigainai.

No matter what you eat at this restaurant, it's delicious, so you can't go wrong choosing it.

Kare wa mainichi osoku made renshuu shite iru kara, kondo no shiai de katsuyaku suru ni machigainai.

Since he practices late every day, he is sure to play an active role in the next match.