The matrix A is 4 x 4 and row reduces to the identity. The matrix B is 3 x 3 and the solution to B = b is a plane in R³. Include the following in your initial post: For A and B, answer the following questions: 1. Is the matrix invertible? How do you know? Use a theorem from the readings or videos. 2. What is the rank of the matrix? Justify your reasoning. 3. How many solutions are there to Ax=0? Explain how you know. Use a theorem from the reading or videos.

Can you please give a explanation of why the rank of B is 2 and how you find the rank and what is the definition. 

Thank You.