How to add rational numbers with different denominator ? How to add rational numbers with same denominator ?

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Two cyclists 84 miles apart start riding toward each other at the samen time. one cycles 2 times as fast as the other. if they meet 4 hours later what is the speed (in miles) of the faster cyclists

Acd that is originally priced at $15.85 red-tagged for the sale. what is the sale price of the cd

Line wx is parallel to line yz. if m