Final answer:
The linear equation that represents Jill's total daily pay is P = 12x + 60.
Step-by-step explanation:
The linear equation that represents Jill's total daily pay is P = 12x + 60. In this equation, P represents Jill's total pay for the day, and x represents the number of phones she sells. The coefficient of 12 in front of x represents the amount she earns per phone sold, and the constant term of 60 represents her base salary for the day.