es s in terms if B. C and 31. [The matrix A is called Heck upper triangular.) Hints. First get an idea. of what the solution should look like...

 Let B and D be invertible matrices of sizes m × m and n × n, respectively, and let C be any m × n matrix. Find the inverse of

es s in terms if B". C and 3—1. [The matrix A is called Heck upper triangular.) Hints. First get an idea. of what the solution should look like by considering the esse when E, C, and D are scalars. For the matrix ease your goal is to find matrices W", X. Y , 3 {in terms of 3—1,0.. and [Ii—1} that satisfy AW X]=r Y 3 Use block matrix multiplication to express this as s set of four matrix equations that you can thensolve. The method you will find is sometimes called black back substitute-rs.