2 -3 -7 5 2 -2] [1 0 -2 1 1 -2 -4 3 1 -2 1 -1 2 |1 -5 -7 6 2 -7 R: 0 0 0 0 -4 2 3 1 1 Again you may use, without justification, the fact that R is the reduced echelon form of A. Consider the following...

Extracted text: 2 -3 -7 5 2 -2] [1 0 -2 1 1 -2 -4 3 1 -2 1 -1 2 |1 -5 -7 6 2 -7 R: 0 0 0 0 -4 2 3 1 1 Again you may use, without justification, the fact that R is the reduced echelon form of A. Consider the following five vectors in R4: ai a2 az = a5 a6 |1: (a) Does ag belong to the span of a1, a2, and a5? If not, explain why not; if so, write ag explicitly as a linear combination of a1, a2, and a5. (b) Are a1, a2, and az linearly independent? If so, explain why; if not, provide a nontrivial linear depen- dence relation among a1, a2, and a3.