It's y=kx. But 'k' is any constant. So my 'k' can easily be 1/(your k). The key is that when 'x' or 'y' increases by some factor, the other one also increases, by some constant multiple of the same factor. If so, then they're proportional.
Assignment: 
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Answer: 
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Explanation: 
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Note: 
[ Step One ] Multiply Both Sides By 9

[ Step Two ] Simplify

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Slope = rise/run = 10/50 = 1/5
Answer:
15 miles
Step-by-step explanation:
8.80-2.80=6
6/0.40=15 miles
Answer:
sqrt. 244
Step-by-step explanation:
a^2 + b^2 =c^2
10^2 + 12^2 =244
c^2 =244
c= sqrt. 244