SOLUTION: How do I set up a formula to the problem: Two planes leave Los Angeles at the same time. One heads south to San Diego, while the other heads to San Fransisco. The San Diego Plan

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Question 396192: How do I set up a formula to the problem: Two planes leave Los Angeles at the same time. One heads south to San Diego, while the other heads to San Fransisco. The San Diego Plane flies 50 mph slower than the San Francisco plane. In 1/2 hour, the planes are 275 miles apart. What are their speeds? I know rate times time equals distance. So how would the equation be set up on this problem with the planes being 275 miles apart going different speeds?
Answer by CharlesG2(834) About Me  (Show Source):
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How do I set up a formula to the problem: Two planes leave Los Angeles at the same time. One heads south to San Diego, while the other heads to San Fransisco. The San Diego Plane flies 50 mph slower than the San Francisco plane. In 1/2 hour, the planes are 275 miles apart. What are their speeds? I know rate times time equals distance. So how would the equation be set up on this problem with the planes being 275 miles apart going different speeds?

Distance = Rate * Time
rate SD = rate SF - 50, SD = San Diego, SF = San Francisco
SF * 0.5 + (SF - 50) * 0.5 = 275
0.5SF + 0.5SF - 25 = 275
SF = 300 mph --> speed of San Francisco plane
SD = SF - 50 = 300 - 50 = 250 mph --> speed of San Diego Plane
SF went 150 miles north
SD went 125 miles south
that is 275 miles apart