Answer:
9x + 4.5y if .5y is a decimal point, 9x + 9y if the dot is a typo
Explanation:
If the dot is real,
7x + 3x + 4y - x + 0.5y
10x + 4y - x + 0.5y
10x - x + 4y + 0.5y
9x + 4.5y
If the dot is a typo,
7x + 3y + 4x - x + 5y
10x + 4y - x + 5y
10x - x + 4y + 5y
9x + 9y