Math 2318 Secs. 1.3,1.5, 1.7 Type questions, also resolved quickly using ref

Any question that can be rephrased as "Solve Ax=b" can be quickly solved using rref (assuming you know what to do with its output, which this video discusses). Questions about whether a vector belongs to the span of other vectors or whether a set of vectors forms a linearly independent set can also be so rephrased, easily IF you know your definitions.