# 15.3 verify that dim(NS(A)) + Rank(A) = 5

#### karush

##### Well-known member
15.3 For the matrix
$$A=\begin{bmatrix} 1 & 0 &0 & 4 &5\\ 0 & 1 & 0 & 3 &2\\ 0 & 0 & 1 & 3 &2\\ 0 & 0 & 0 & 0 &0 \end{bmatrix}$$
(a)find a basis for RS(A) and dim(RS(A)).
ok I am assuming that since this is already in row echelon form, its nonzero rows form a basis for RS(A) then
So...
$$RS(A)=(1,0,0,4,5),\quad(0,1,0,3,2),\quad(0,0,1,3,2)$$
also
dim(RS(A))= ??

(b)verify that dim(NS(A)) + Rank(A) = 5.

ok I am a little unsure what this means