SOLUTION: two small planes start from the same point and fly in opposite directions. the first plane is flying 40mph slower than the second plane.in 2h,the planes are 250mi apart.Find the ra

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Question 670468: two small planes start from the same point and fly in opposite directions. the first plane is flying 40mph slower than the second plane.in 2h,the planes are 250mi apart.Find the rate of the slower plane.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
They are moving apart at the sum of their speeds
Let +s+ = the speed of the second plane
+s+-+40+ = the speed of the 1st plane
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+250+=+%28+s+%2B+s+-+40+%29%2A2+
+250+=+4s+-+80+
+4s+=+330+
+s+=+82.5++
+s+-+40+=+82.5+-+40+
+s+-+40+=+42.5+
the slower plane is flying at 42.5 mi/hr
check:
+250+=+%28+s+%2B+s+-+40+%29%2A2+
+250+=+%28+82.5+%2B+42.5+%29%2A2+
+250+=+125%2A2+
+250+=+250+
OK