LA2Quick check●○○○○new1 Quotients and direct sumsFind dimR5/U\dim\mathbb{R}^5/UdimR5/U where U={x∈R5:x1=x2=0}U = \{x\in\mathbb{R}^5: x_1 = x_2 = 0\}U={x∈R5:x1=x2=0}.