Find a basis for the subspace R3 defined by
{(3a,5b,2a-b): a,b are members of R}
What is " "?
When you are given a set in a general form you can quite easily come up with a spanning set. You just split up the general form into vectors containing one and only one of the variables. For instance, " ", and then take out the variables and you will have yous spanning set. So here " " would become " " which is a member of your spanning set.
You then have to ask if this spanning set is a basis or not. That is, is it linearly independent.