Question: In Exercises, find a basis and the dimension of the given subspace S.
Exercise: 1. The subspace S of vectors in R5 of the form (x1, x2, x3, x4, x5) with x1 = x2 = 2x3.
2. The subspace S of vectors in R6 of the form (x1, x2, x3, x4, x5, x6) with x1 = 2x2 and x3 = -x4.