數學(A)

(10%) Let $U = \text{span}\{(1,3,-2,2,3),(1,4,-3,4,2),(2,3,-1,-2,9),(2,4,-2,0,8)\}$ and $W = \text{span}\{(1,3,0,2,1),(1,5,-6,6,3),(2,5,3,2,1),(2,7,-3,6,3)\}$ be two subspaces of $\mathbf{R}^5$. The dimension of $U \cap W$ is