What are a and b from expression a + b + 2i = i*a - i*b + 6 ?

To find a and b in a+b+2i =
i*a-i*b+6

We know i  =
sqrt(-1).

a+b +2i =  i*a- i*b
+6.

We write both sides in  x+yi form where x is real part
and y is imaginary part.

(a+b) +2i = 6
+(a-b)i.........(1)

We equate real parts on both side of
(1):

a+b = 6...........(2)

We
equate imaginary parts on both sides of (1):

2 = a-b.
Or

a-b =
2...............(3)

Adding eq(2) and (3) we
get:

2a = 8

a = 8/2 =
4

Eq(2) - eq(3) gives:

2b =
6-2 = 4.

b = 4/2 = 2

Therefore
a = 4 and b = 2.