U=???????a+ba?bba?????a and b in R???? c. U=???????abc+ac?????a,b, and c in R???? d. U=???????ab+cb+c?????a,b, and c in R???? e. U=???????a?bbbd?????a+b?c+d=0 in R???? e U} f. U=???????abcd?????a+b=c+d in R?????
Exercise 5.3.4 Find a basis and calculate the dimension of the following subspaces of R4. a. U=???????aa+ba?bb?????a and b in R}
![\( \begin{array}{l}U=\left\{\left[\begin{array}{c}a+b \\ a-b \\ b \\ a\end{array}\right] \mid a \text { and } b \text { in }](https://media.cheggcdn.com/study/4c0/4c0ebf35-1681-4ee3-a46b-3ef9acd8a6aa/image)
