SOLUTION: Please help me set up this problem:
"When Ace Airlines changed to planes that flew 100km/hour faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced
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-> SOLUTION: Please help me set up this problem:
"When Ace Airlines changed to planes that flew 100km/hour faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced
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Question 427559: Please help me set up this problem:
"When Ace Airlines changed to planes that flew 100km/hour faster than its old ones, the time of its 2800 km Dallas-Seattle flight was reduced by 30 minutes. Find the speed of the new planes." Answer by mananth(16946) (Show Source):
You can put this solution on YOUR website! original speed = x
increased speed = x+100
...
Original time = 2800/x
Time after speed increase = 2800/(x+100)
2800/x - 2800/(x+100)=1/2
LCD = x(x+100)
multiply by x(x+100)
2800(x+100)-2800*x= 1/2* x(x+100)
2800x+280000-2800x=1/2(x^2+100x)
5600x+560000-5600x= x^2+100x
x^2+100x-560000=0
Find the roots of the equation by quadratic formula
