SOLUTION: z is jointly proportional to x2 and y2. If z = 422 when x = 6 and y = 7, find z when x = 5 and y = 5.

Algebra ->  Real-numbers -> SOLUTION: z is jointly proportional to x2 and y2. If z = 422 when x = 6 and y = 7, find z when x = 5 and y = 5.      Log On


   

Question 1050642: z is jointly proportional to x2 and y2. If z = 422 when x = 6 and y = 7, find z when x = 5 and y = 5.
Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
z = k * x^2 * y^2
:
422 = k * 6^2 * 7^2
:
k = 422 / (36 * 49) = 0.2392
:
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z = 0.2392 * 5^2 * 5^2 = 149.5
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