Give a geometric description of the following systems of equations

Select Answer Three identical planes Three planes with no common intersection Three planes intersecting at a point Three planes intersecting in a line  1. $\left\lbrace\begin{array}{rrrrrrrr}& - \, x&- &4 \,y&- &12 \,z&=&7\\& - \, x&- &3 \,y&- &9 \,z&=&0\\& 4 \,x&+& 16 \, y&+& 44 \, z&=&1\\ \end{array}\right.$

Select Answer Three identical planes Three planes with no common intersection Three planes intersecting at a point Three planes intersecting in a line  2. $\left\lbrace\begin{array}{rrrrrrrr}& \,x&+& \, y&+& 7 \, z&=&1\\& 3 \,x&+& 3 \, y&+& 4 \, z&=&2\\& 13 \,x&+& 13 \, y&+& 23 \, z&=&9\\ \end{array}\right.$

Select Answer Three identical planes Three planes with no common intersection Three planes intersecting at a point Three planes intersecting in a line  3. $\left\lbrace\begin{array}{rrrrrrrr}& \,x&+& \, y&+& 7 \, z&=&1\\& 3 \,x&+& 3 \, y&+& 4 \, z&=&2\\& 13 \,x&+& 13 \, y&+& 23 \, z&=&14\\ \end{array}\right.$

Select Answer Three identical planes Three planes with no common intersection Three planes intersecting at a point Three planes intersecting in a line  4. $\left\lbrace\begin{array}{rrrrrrrr}& 4 \,x&+& 8 \, y&+& 8 \, z&=&-6\\& 10 \,x&+& 20 \, y&+& 20 \, z&=&-15\\& -14 \, x&- &28 \,y&- &28 \,z&=&21\\ \end{array}\right.$