Final answer:
The slope of the phone plan is 1, representing the increase in cost per extra minute used. The y-intercept is 40, representing the fixed cost of the phone plan.
Step-by-step explanation:
The slope of the phone plan is given by the coefficient of the variable 'm' in the equation. In this case, the slope is 1, which means that for every additional minute used, the monthly cost increases by $1.
The y-intercept of the phone plan is given by the constant term in the equation, which is 40. This represents the fixed cost of the phone plan, regardless of the number of extra minutes used.