Due to presence of two or more sources circuit becomes difficult for solving and in such cases circuit is solved by applying superposition theorem.
In Superposition theorem, we solve the circuit with one source at one time (with other source replaced by its internal resistance). Voltage source has zero internal resistance (If not given) and Current source has infinite internal resistance (if not given). Hence Voltage source is Short-circuited(shorted) and Current source is Open circuited (opened).
Nitin Phadkule (2022). Superposition Theorem tab app (https://www.mathworks.com/matlabcentral/fileexchange/94570-superposition-theorem-tab-app), MATLAB Central File Exchange. 取得済み .