Expert: Paul Klarreich - 8/25/2009

Question
I don't know where to begin.  I do know how to write linear equations if given more information.  I am totally lost on this one.  Can you please help?


Linda needs 2100 calories per day to maintain her present weight and daily activites.  She wants to lose x pounds per day.  Each pound of body weight lost is equivalent to 3500 calories.  Write her daily calorie intake as a linear function of the number of pounds of weight lost per day.

Answer
Questioner: Dedra
Country: United States
Category: Advanced Math
Private: No
Subject: FINITE MATH: linear equation word problem
Question: I don't know where to begin.  I do know how to write linear equations if given more information.  I am totally lost on this one.  Can you please help?


Linda needs 2100 calories per day to maintain her present weight and daily activites.  She wants to lose x pounds per day.  Each pound of body weight lost is equivalent to 3500 calories.  Write her daily calorie intake as a linear function of the number of pounds of weight lost per day.
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Hi, Dedra,

Start by identifying the variable. ['x' is not a variable, it is just its name.]

Let x = the number of pounds to be lost each day.

Then write values in the example in terms of the variable.

Then  3500x = the number of calories to reduce each day.

And  2100 - 3500x = the caloric intake to do that.