Thanks for your feedback. I will see if I can figure it out with your recommendations. No it's supposed to be grounded but the quality of their printouts are horrible. Just to clarify you are referring to question 1 right? I redrew my sketch so that the 9V is grounded correctly.
I just saw my error that I made. I think I did it correctly in the other questions, but not with sim equations. I will update this question and resend.
I think this is how it is done. Forget R3 R5 R6.
Short V2 and using thev you get 2.25V with 0.75 ohm
Short V1 and as above you get 5.625V with 0.75 ohm
Add the voltages and parallel the resistors and you get 7.785V with 0.375ohm
Total current through the loop is 7.785/(0.375 + 3 +4 +10) = 0.4532A
Across the 10ohm using V=IR gives 4.532V
Not sure if method is correct as there is 30 years between learning and doing this, but LT Spice comes pretty close. I would be interested in an alternate method.
Q4. 0.41A. Sorry no clues yet.
Now it's time you did your homework and worked it out for yourself. You have enough with my examples. Please come back if you're stuck and I will explain further.