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 $\displaystyle -j-0.609$ would be interpreted as minus $\displaystyle j$ minus $\displaystyle 0.609,$ that is, two separate terms. And you have two negative signs when there should just be one.
The correct form should be $\displaystyle -j0.609$ or $\displaystyle -0.609j.$ 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 $\displaystyle 1/Z_{3}$ line immediately above. Write it as $\displaystyle 1/Z_{3}=j(-1/6),$ it's a multiplication not a subtraction.