If we make some assumptions about what your questions and answers are, it appears some adjustments may be needed.
Q: What is the equation that gives Alyssa's daily earnings?
A: If we use y for daily earnings and x for sales, the equation would be
... y = 0.15x + 80 . . . . . . . . . your equation is missing an "x"
Q: What does the y-intercept of the graph represent?
A: Alyssa's earnings if she makes no sales
Q: What does the slope of the line represent?
A: The commission Alyssa receives on sales (her rate of increase of earnings as a function of her sales)
Q: What is the y-intercept?
A: 80 . . . . . . correct