i’m really confused please help

Answer:
(2). b - (a + c)i
Step-by-step explanation:
[tex]i^{7}[/tex] = [( i )²]³ × i = ( - 1)³ i = - i
[tex]i^{16}[/tex] = [tex]((i)^2)^{8} = ( - 1)^{8} = 1[/tex]
[tex]((i)^2)^{10}[/tex] × i = i
a(- i ) + b( 1 ) - c( i ) = - ai + b - ci = b - (a + c)i