Hello there!
(87.5y + 12.2x) - (54.3y + 13.9x)
You wanna start by distributing the negative sign
87.5y + 12.2x - 54.3y - 13.9x
Combine the like terms
12.2x - 13.9x + 87.5y - 54.3y
= -1.7x + 33.2y
Let me know if you have any questions. As always, it is my pleasure to help students like you!