Question

So i'm doing a mock test in preparation for a class test i have next week. Just have a couple questions, i have an attachment:

i) I said they are LI because theres no combination to get an all zero row, and that they dont span r3 as you need at least

ii) I formed the equations to show that they all equal zero, but is there a quicker way to show if they are LI / span r3 rather than put it all into REF?