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) About Me  (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