# Writing an equation for this problem?

Suppose you are preparing a snack mix. You want the total protein from peanuts and granola to equal 28 grams. Peanuts have 7 grams of protein per ounce, and granola has 3 grams of protein per ounce.

I'm pretty sure it's 3g + 7n = 28

I may be wrong.

Now I have to graph it, do I change it? If I do, how?

sciencesolve | Certified Educator

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The equation provided is good and you need now to sketch a graph, hence, you should write either g in terms of n, or n in terms of g such that:

`3g + 7n = 28`

`3g = 28 - 7n => g = (28-7n)/3`  (write g in terms of n)

or

`3g + 7n = 28`

`7n = 28 - 3g => n = (28-3g)/7`  (write n in terms of g)

You need to sketch the graph of the linear function `g = (28-7n)/3`  such that:

You need to sketch the graph of the linear function `n = (28-3g)/7`  such that:

Notice that the functions `n = (28-3g)/7`  and `g = (28-7n)/3`  are inverses to each other.

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