z1 = 2 + j2
z2 = 1 + j5
z3 = j6
what is Y when :
Y = (1/z1) + (1/z2) + (1/z3)
1/z3 how is that done??????
Not totally correct, though the decimal values are correct.
The end of that last line would be interpreted as minus minus that is, two separate terms. And you have two negative signs when there should just be one.
The correct form should be or I prefer the second one though I know the purists will say that the first is correct.
You make more or less the same mistake in the line immediately above. Write it as it's a multiplication not a subtraction.