Forming linear equations from word problems?

Question

Sam purchased a new iphone. The cell phone company charges $50 a month for cell phone service, $200 for the phone, and a charge of $175 if the contract is terminated before 2 years have expired. Which of the linear equations corresponds Sam's total in dollars, Y, as a function of the number or months after she purchased the phone, x , if she terminates her contract before 2 years? 

Answer 1

Y = M*X + P + C  where  

 

M = monthly charge = $50

P = phone cost = $200  

T = termination charge = $175 

 

Y = 50*X + 200 + 175 = 50*X + 375