。
I had been taught to cheat.
Literal
I [topic-は] cheating [object-を] do [thing-こと-を] was-being-taught [explanatory-のだ].
Passive voice with a heavy explanatory tone. 教えられていた = passive of 教える + ~ていた, expressing the past ongoing state of having been taught. The のだ at the end frames this as a confession or revelation — 'the truth is, I had been taught...' インチキ ('cheating, fraud') is loanword-feeling but actually native; common in casual speech.