Understand the problem carefully which is the only solution you have when you construct equations depicting the relationship between variables. For this problem, the equation would be:
y = 65 + 10x
where x is the number of years
y is the cost
The slope-intercept form equation is y = mx + b, where m is the slope and b is the intercept. Therefore, in this problem, the slope is 10 and the y-intercept is 65.
