Please explain each step, thanks

4) Write an expression that gives the matrix P that projects a vector from R* onto the column 4 space of the matrix AUIN Then write an expression for the projection of onto that space. (Note: you do not need to fully calculate any inverses, nor P or p, as long as they are written as a product of matrices and/or vectors.) 5) Let u = Find an orthonormal set of vectors that span the same space as { u, v, w}. (Note that u . v = 0) 6) Prove whether or not each set is a subspace of IR3: * ] a. S1: The set of vectors y where x = 2y = 3z b. $2: The set of vectors y where x = y? = 23