Slope intercept form (y = mx + b) requires that we have a slope and y intercept. The slope is the rate at which the company grows (12.5 employees/month) and the y intercept is the number of employees the company started with. After one year, the company would have gained 12.5 employees every month. That is 12.5*12 = 150 employees.
After a year the company had 224 people, so we can find the initial amount by subtracting the total amount vby the amount gained. 224 - 150 = 74.
So in slope intercept form:
y = 12.5x + 74
