Alex Kate, Kelzy, and Lily are collecting dog toys for Scarlett. Their toy collection goal is represented by the expression `16x^{2}-3xy-6`. The friends have already collected the following number of toys:
Alex Kate: `6x^{2}`
Kelzy: `4x^{2}-2xy`
Lily: 4xy + 3

Part A: Write an expression in standard form to represent the amount of toys collected so far by the three friends. Show all your work. (5 points)

Part B: Write an expression in standard form that represents the number of toys the friends still need to collect to meet their goal. Show all your work. (5 points)