-) Let H be a subspace of R4 given as Find a basis for H. What is the dimension of H? \text { 1.b) You are given that } A=\left[\begin{array}{lllll}

1 & 1 & 1 & 0 & 2 \\ 2 & 5 & 5 & 2 & 2 \\ 1 & 2 & 2 & 1 & 1 \end{array}\right] \sim\left[\begin{array}{llllr} 1 & 0 & 0 & 0 & 2 \\ 0 & 1 & 1 & 0 & 0 \\ 0 & 0 & 0 & 1 & -1 \end{array}\right]=B \text { . } Find a basis for ColA. What is dim(ColA)?