SOLUTION: If y varies directly with x and y = -7 when x = -1, find x when y = -84.
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Question 549840: If y varies directly with x and y = -7 when x = -1, find x when y = -84.
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
y = kx
-7 = k(-1)
-7/(-1) = k
7 = k
k = 7
So the equation is y = 7x
So when y = -84, then
y = 7x
-84 = 7x
-84/7 = x
-12 = x
x = - 12
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