Question 375577
let them hike uphill at x mph
downhill they hike x+2 mph
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distance = 3 miles
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time up + time down = 4 hours
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t = d/r
{{{3/x  + 3/(x+2) =4}}}
LCD = x(x+2)
multiply the equation by x(x+2)
{{{(3*(cross(x))*(x+2))/((cross(x))) + (3*x*(cross(x+2)))/((cross(x+2)))=4*x(x+2)}}}
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3(x+2)+3x=4x^2+8x
3x+6+3x=4x^2+8x
reorganize
4x^2+2x-6=0
/2
2x^2+x-3=0
2x^2+3x-2x-3=0
x(2x+3)-1(2x+3)=0
(x-1)(2x+3)=0
x=1 OR x=-3/2
ignore negative
uphill rate = 1 mph
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m.ananth@hotmail.ca