Computer Mathematics and the Graphing Calculator

It is acceptable to have 3/5 or –3/5 but not acceptable to have 3/-5 or –3/-5. The simplest and most efficient method would be to take the opposite of the numerator and denominator in any fraction where the denominator is negative. That would change 3/-5 to –3/5 and would change –3/-5 to 3/5. ................
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