SOLUTION: Suppose p varies jointly as r and t. If p = 1 when r = -5 and t = 2, find t when p = 6 and r = 12. A. -5 B. -7.2 C. -6.4 D -5.4

Algebra ->  Test -> SOLUTION: Suppose p varies jointly as r and t. If p = 1 when r = -5 and t = 2, find t when p = 6 and r = 12. A. -5 B. -7.2 C. -6.4 D -5.4      Log On


   

Question 436235: Suppose p varies jointly as r and t. If p = 1 when r = -5 and t = 2, find t when p = 6 and r = 12.
A. -5
B. -7.2
C. -6.4
D -5.4
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi

Suppose p varies jointly as r and t. If p = 1 when r = -5 and t = 2

   p = krt where k is th econstant of proportionality

   1 = k*-5*2

  1/-10 = k = -.1    | p = -.1rt

find t when p = 6 and r = 12.

  p = -.1rt

  p/-.1r = t

  t = p/-.1r  

  t = 6/(-.1*12) = 6/-1.2 = -5       when p = 6 and r = 12