This problem is due tomorrow, i need help.

Letting T: R^4 -> R^3, where T(v)=Av.

Matrix A: 2, 1, -1, 1

1, 2, 0, 5

4, -1, -1, 0

note: this is a 3x4 matrix.

Find: Kernel(T), Nullity(T), Range(T), Rank of T, Rank of matrix A.

Some things I know about this problem:

Ker(T) = Null(A).

The 3rd row of the matrix has to all be zeros.

The problem I am having most is, reducing matrix A into its reduced form or whatever it's called.

Please help..