First, please use clearer titles when making a post. Titles such as "PLZ HELP" do not provide an accurate idea of what the question will be about - basically, a title that introduces your question makes it easier for people to find your post and provide a good answer to your questions.
Now, do you know what the quadratic formula is? Do you know what it is used for? If so, then writing the code should be very simple - all it requires is some basic knowledge of the arithmetic operators and variables in C.
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