Which of the following statements are true?
A. The equation Ax = b is referred to as a vector equation.
B. A vector b is a linear combination of the columns of a matrix A if and only if the equation Ax = b has at least one solution.
C. The first entry in the product Ax is a sum of products.
D. The equation Ax = b is consistent if the augmented matrix [Ab] has a pivot position in every row.
E. If the columns of an m \times n matrix A span {\mathbb R}^m, then the equation Ax = b is consistent for each b in {\mathbb R}^m.
F. If A is an m \times n matrix whose columns do not span {\mathbb R}^m, then the equation Ax = b is inconsistent for some b in {\mathbb R}^m.

Respuesta :

Answer:

B, C, E, & F

Step-by-step explanation:

Option A is incorrect because the equation Ax = b is referred to as a matrix equation, not a vector equation.

Option B is correct. If Ax = b has a solution, vector b will a linear combination of columns of matrix A.

Option C is correct. In a matrix equation, product Ax when defined, is a sum of products.

Option D is incorrect. If an augmented matrix [Ab] had a pivot position in every row, there could be a pivot in the last column which would make it inconsistent.

Option E is correct. If the columns of an m×n matrix A span[tex] R^m[/tex], then the equation Ax=b is consistent for each b in

Option F is correct. IfA is an m x n matrix whose columns do not span, then the equation Ax = b is inconsistent for some b in [tex] R^m[/tex]

Options B, C, E, and F are correct.