(Solved): The following three problems pertain to this circuit for which you should use node-voltage anal ...

The following three problems pertain to this circuit for which you should use node-voltage analysis to obtain a solution. A) Solve for $i_x$ in the circuit shown above. B) Solve for $i_x$ in the circuit shown above. However, instead of using the circuit as drawn, replace the $8\mathrm{A}$ source with a $30\mathrm{V}$ voltage source. The higher polarity terminal of the voltage source should be "up" and the lower polarity terminal "down." Other than changing this one source, there are no other changes to the circuit. c) Solve for $i_x$ in the circuit shown above. However, instead of using the circuit as drawn, replace the dependent current source with a $20\mathrm{V}$ voltage source. The lower polarity should be to the left and the higher polarity should be to the right. Other than changing this one source, there are no other changes to the circuit.