Simplify (2i1+i)2
We have,
(2i1+i)2
⇒4i21+i2+2i
⇒−41−1+2i(∵i2=−1)
⇒−42i
⇒−2i
⇒−2ii2
⇒−2i−1
⇒2i
Hence, this is the answer.