Faster way to solve a system of four equations and four unknowns

[Icelerate]

1. Solve it by elimination
2. Solve it by substitution
3. Solve it by row reduction and back substitution
4. Solve it by reducing the matrix to Row reduced echelon form

I think option 3 is the fastest followed closely by option 1. Although I think option 2 is the safest way of getting the right answer.