# Algebra

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## Algebra

 ------------------------- Two planes just took off from Boston Ma the first plane is traveling 1.5 times as fast as the second plane . After traveling in the same direction for 9 hours  they are 387 miles apart . What is the average speed of each plane ?
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## Re: Algebra

 Assuming they left at the same time and are traveling in the same direction: distance = rate x time First Plane d = rt rate = 1.5r   {1.5 times as fast as second plane} time = 9   {traveled for 9 hours} d = 1.5r(9)   {distance = rate x time} d = 13.5r Second Plane d = rt rate = r   time = 9   {traveled for 9 hours} d = 9r   {distance = rate x time} In 9 hours, the first plane will be 387 miles in front of second plane. 13.5r = 9r + 387   {first plane equals second plane plus 387} 4.5r = 387   {combined like terms} r = 86   {divided each side by 4.5}   Rate of second plane is 86.1.5r = rate of first plane = 1.5(86)   {substituted 86, in for r, into 1.5r} = 129   {multiplied} 129 mph is rate of first plane- Algebra House