Determine the value of the missing sides for the following triangle

Let $x be the amount of money which Kelci has raised. Brianna has raised 3 times more money than kelci, then she has raised $3x. Totally both have aised $(x+3x)=$4x.

Since together they have raised more than $300, then 4x>300,

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the inequality  can be used to determine the amount of money kelci has raised