SOLUTION: The cell phone crevice for a business executive is $80 per month plus $0.40 per minute of phone use over 900 min. In a month when the executive's cell phone bill was $110.40, how m

Algebra ->  Human-and-algebraic-language -> SOLUTION: The cell phone crevice for a business executive is $80 per month plus $0.40 per minute of phone use over 900 min. In a month when the executive's cell phone bill was $110.40, how m      Log On


   



Question 994233: The cell phone crevice for a business executive is $80 per month plus $0.40 per minute of phone use over 900 min. In a month when the executive's cell phone bill was $110.40, how many minutes did the executive use the phone?
My teacher didn't teach us how to solve these sorts of problems so I'm really stuck. Thank you for taking time to help!

Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
.
x=total minutes of use
.
When x>900:
Bill=$80+$0.40(x-900)
Bill=$80+$0.40x-$360
Bill=$0.40x-$280
.
$110.40=$0.40x-$280
$390.40=$0.40x
976=x
ANSWER: He used the phone 976 minutes.