Answer:
72
Step-by-step explanation:
bacause the equation of area of square is a^2 and 12×12=144 so each side is 12 feet and the height is 6 making it 12×6 so 72 square feet
Answer:
Hope that will help you get
Answer:

Step-by-step explanation:
You cannot add row 2 to column 3 because they have different dimensions. You can do any of the other operations, but the only one that makes any sort of sense is ...
Multiply row 2 by -1 and add it to row 3
_____
It makes no sense to multiply a row by zero. That makes the entire row zero and makes the matrix useless for finding any sort of solution.
You can switch columns, but that doesn't get you any closer to a solution here.
If I were trying to find a solution, I might
switch rows 1 and 2
multiply the new row 1 by -3 and add it to the new row 2
multiply the new row 1 by 2 and add it to row 3
This sequence of operations will make the first column [1 0 0], reducing the problem to 2×2 from 3×3.