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finding a basis for a row space and rank in exercises 5, 6, 7, 8, 9, 10, 11, and 12, find (a)a basis for the row space and (b)the rank of the matrix.

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Here are the bases and ranks for matrices in exercises 5, 6, 7, 8, 9, 10, 11, and 12.Exercise 5The given matrix is$$\begin{bmatrix} 1&3&3&2\\-1&-2&-3&4\\2&5&8&-3 \end{bmatrix}$$(a) Basis for row spaceFor finding the basis of row space, we perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&3&3&2\\0&1&0&3\\0&0&0&0 \end{bmatrix}$$Now, we can see that the first two rows are linearly independent. So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 1&3&3&2\\-1&-2&-3&4 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have two non-zero rows. Therefore, the rank of the matrix is 2.Exercise 6The given matrix is$$\begin{bmatrix} 1&2&0\\2&4&2\\-1&-2&1\\1&2&1 \end{bmatrix}$$(a) Basis for row spaceWe perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&2&0\\0&0&1\\0&0&0\\0&0&0 \end{bmatrix}$$Now, we can see So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 2&1&-3\\1&3&2\\0&-1&7 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have three non-zero rows. Therefore, the rank of the matrix is 3.Exercise 11The given matrix is$$\begin{bmatrix} 1&1&2\\-1&-2&1\\3&5&8\\2&4&7 \end{bmatrix}$$(a) Basis for row spaceWe perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&1&2\\0&-1&3\\0&0&0\\0&0&0 \end{bmatrix}$$Now, we can see that the first two rows are linearly independent. So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 1&1&2\\-1&-2&1 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have two non-zero rows. Therefore, the rank of the matrix is 2.Exercise 12The given matrix is$$\begin{bmatrix} 1&2&3&4\\2&4&6&8\\-1&-2&-3&-4\\1&1&1&1 \end{bmatrix}$$(a) Basis for row spaceWe perform row operations on the given matrix and get the matrix in echelon form.$$ \begin{bmatrix} 1&2&3&4\\0&0&0&0\\0&0&0&0\\0&0&0&0 \end{bmatrix}$$Now, we can see that the first row is non-zero. So, the basis for row space of the matrix is$$\left \{ \begin{bmatrix} 1&2&3&4 \end{bmatrix} \right \}$$(b) Rank of matrixThe rank of the matrix is equal to the number of non-zero rows in the echelon form. Here, we have one non-zero row. Therefore, the rank of the matrix is 1.

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