<PRE><B>Question 478091</B>
first part x-5 mph 195 miles

second part x+5 mph 195 miles

195/(x-5)-195/(x+5) = 0.4 hours

LCD = (x+5)(x-5)
Multiply equation by LCD

195/(x+5)-195/(x-5)= (x+5)(x-5)*0.4

195x+975-195x+975=0.4(x^2-25)

1950=0.4x^2-10
1960=0.4x^2
1960/0.4=x^2
4900 = x^2

x= 70 mph the speed limit

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