I'll be happy to validate you once you have addressed the units issue (as anyone around here can confirm, I am big on tracking units properly) and a few other things.
You need to:
1) Turn your expressions into equations by giving them an appropriate left-hand side (LHS).
2) Correct the "μΩ" units in those places where they should be "μS".
3) Add units in the places where you have omitted them (such as the RHS of line 4, which has units of MΩ, and the RHS of line 7, and all four lines where you calculate the individual currents).
4) Add a "Checks" section to the end of your work in which you check your answer by adding up all four currents and comparing the total to the given total current. Get in the habit of putting checks like that at the end of every problem you can, even on exams (especially on exams!). You will catch almost all your errors and even if you can't correct the work (out of time on an exam, for instance) you will often get significant partial credit for catching the error.
You need to:
1) Turn your expressions into equations by giving them an appropriate left-hand side (LHS).
2) Correct the "μΩ" units in those places where they should be "μS".
3) Add units in the places where you have omitted them (such as the RHS of line 4, which has units of MΩ, and the RHS of line 7, and all four lines where you calculate the individual currents).
4) Add a "Checks" section to the end of your work in which you check your answer by adding up all four currents and comparing the total to the given total current. Get in the habit of putting checks like that at the end of every problem you can, even on exams (especially on exams!). You will catch almost all your errors and even if you can't correct the work (out of time on an exam, for instance) you will often get significant partial credit for catching the error.