(Algebra II) extra points!!Find the value of y for a given value of x, if y varies directly with x.
If y = -252 when x = 84, what is y when x = 74?
Please explain/show your work if you can
Everything helps!! Giving brainliest!! TIA:)

Respuesta :

Answer:

  -222

Step-by-step explanation:

The new value of x is 74/84 of the old value, so the new value of y will also be 74/84 of the old value:

  (74/84)·(-252) = -222

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If you like, you can solve for the constant of proportionality (k) in the equation ...

  y = kx

  -252 = k(84)

  -252/84 = k = -3

Then you can use this equation to find the new value of y.

  y = -3·74 = -222

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As we have seen above, there is no need to discover the value of k if there is only one new x-value to be concerned with. If you have to find y for a number of new x-values, then it can be useful to know what k is.