(Solved): A matrix \( A \) and an echelon form of \( A \) are shown below. Find a set that spans Nul \( A \). ...

A matrix \( A \) and an echelon form of \( A \) are shown below. Find a set that spans Nul \( A \). \[ A=\left[\begin{array}{rrrr} 4 & 10 & 10 & -8 \\ 7 & 14 & 7 & 0 \\ 2 & 3 & -1 & 4 \end{array}\right] \sim\left[\begin{array}{rrrr} 1 & 3 & 4 & -4 \\ 0 & 1 & 3 & -4 \\ 0 & 0 & 0 & 0 \end{array}\right] \] (Simplify your answer. Use a comma to separate answers as needed.)