Thread: 7th grade math problem
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rick-l rick-l is offline
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Join Date: May 2002
Location: St Louis
Posts: 4,211
distance = rate * time
t1 = time at 55 mph t2 = time at 40

t1 * 55 + t2 * 40 = 135

t1 + t2 = 3 or t2 = 3 - t1

substitute 2 into 1
t1 * 55 + (3 - t1) * 40 = 135
t1 * 55 - 40 * t1 = 15
t1 = 1
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Rick
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Old 02-25-2014, 10:06 PM
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