Answer:
D: 8x-9y
Step-by-step explanation:
Ok, so lets write out an equation. since the word used is difference, we know we need to subtract: (9x-5y)-(x+4y)
Now we need to combine like terms. This means that we subtract x from 9x and 4y from -5y: 9x-x-5y-4y
Now we just subtract the x and y: 8x-9y
The correct answer would be D: 8x-9y
