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← Joint Variation Practice 2 - Visualizing Algebra

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Showing Revision 2 created 05/25/2016 by Udacity Robot.

  1. With joint variation, though, the variations do not both need to be direct. One
  2. quantity might have direct variation, while the other might have inverse
  3. variation. For example, if x and y had direct variation, they would both
  4. increase, or they would both decrease. And if z varied inversely with x, then if
  5. x increased, z would have to decrease. When setting up the proportion, this
  6. means that since x varies directly with y, they will be directly across from one
  7. another. But since x varies inversely with z, we'll see this z quantity in the
  8. denominator. We flip this fraction. So let's assume this is still true. X is
  9. varying directly with y, and inversely with z. If the value of x is 10 when y
  10. equals 5 and z equals 6. I want you to find the value of x when y is 7 and z is
  11. 1. As a hint, this is one case, this x could be 10, this y is 5, and this z is
  12. 6. So you try and fill in the other values and then solve for x. And keep in
  13. mind in the setup, we had direct variation with y, so this is directly across
  14. from each other Whereas we had inverse variation with c. This c is a
  15. denominator. Write your answer for x here. You can also think about we're really
  16. finding x too, this value. Good luck.