Answer:
C
Step-by-step explanation:
We know it's direct variation using the direct variation equation.

Where k is the constant.
Since 7 times x is the y values, 
Now we can substitute 7 into k of the direct variation equation.

Remark
This may be a little confusing, but because they are travelling in opposite directions, the distances add when you want to get how far apart they are.
d1 + d2 = 1541
Equation
Let the time this happens = t
d1 = 323*t
d2 = 347*t
323*t + 347*t = 1541 Combine like terms on the left.
670t = 1541 Divide by 670
t = 1541/670
t = 2.3 hours pass before the distance of 1541 miles are between the two planes. You might need the answer to be 2 hours 18 minutes.
Answer:
155
Step-by-step explanation: