have you already decided a career vs have you already decided on a career

Some examples from the web:

• I know some of you have already decided you want a good career. You're going to fail, too.
• However, before even finishing his studies, he had already decided on a career in music, embarking on his successful career with "Seeed".
• Have you already decided to delete from your operating system manually?
• Have you already decided who will be in charge of the funeral?
• Have you already decided where to go tomorrow? On another beach or you prefer making an excursion?
• Have you already decided what you're going to tell them?
• We have walked these trails along with guests of Lungolivigno and have collected our experiences in a mini-guide you'll find posted on our website. What about you, have you already decided what your next destination will be?
• And you already decided you're not.
• You already decided to get a divorce.
• Have you already been to Medjugorje?
• Have you already named our children?
• Have you already applied for your fellowships?
• Have you already looked into that?
• Have you already forgotten, sweetheart?
• Usually, we're a great team, but you already decided to go it solo today, so I just followed suit.
• Have you already found a famous director for this?
• Have you already paid the Mellone family?
• If it weren't for these bars, I'd have you already.
• Have you already in your talks found something maybe that you...
• Have you already applied for your fellowships?

Some examples from the web:

• However, before even finishing his studies, he had already decided on a career in music, embarking on his successful career with "Seeed".
• Have you already decided to delete from your operating system manually?
• Have you already decided who will be in charge of the funeral?
• Have you already decided where to go tomorrow? On another beach or you prefer making an excursion?
• Have you already decided what you're going to tell them?
• We have walked these trails along with guests of Lungolivigno and have collected our experiences in a mini-guide you'll find posted on our website. What about you, have you already decided what your next destination will be?
• It's a case we already decided on.
• Amsterdam has already decided on the failure of the national governments.
• But they've already decided on the direction of the ad.
• And they've already decided on your punishment.
• Carl and I already decided on sushi.
• Maw Maw, we already decided on positions.
• I know that we already decided on an open casket, but we should maybe reconsider.
• The UK had already decided on 20 September 2010 to suspend the return of asylum-seekers to Greece.
• Therefore, without realising it, we seem to have already decided on the European Union's negotiating position for future international negotiations.
• Soon - as we of course already decided on 16 March - we should send a European Parliament delegation to Chechnya and that region.
• I had to report on topics that were already decided on, and that's the opposite of reporting.
• It must be pointed out that the African Union itself had already decided on this transfer back in March.
• And you already decided you're not.
• You already decided to get a divorce.