



 
Hi Liz. A direct variation is one where if one quantity goes up, the other quantity goes up and vice versa. An inverse variation is one where one goes down as the other goes up. Generally when you see the term xy, you are dealing with an inverse relationship. For example: xy = 2. If x is 10, then y must be 1/5. If x is 100, then y must be 1/50. If x is 1, then y is 2 and if x is 1/1000, then y is 2000. When things vary directly, then they change size the same way. If x=2y, then when x=5, y=10. If we double x, we double y (10 and 20) and if we reduce to x=1, then y = 1/2. Notice that it is the magnitude of the size, not strictly greater/less than here. For example, the equation Stephen La Rocque.>  


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