<PRE><B>Question 492691</B>
Time to airport + time to home = 2hours

d=40

going speed=x
returning speed= x+30 

{{{(40/x)+(40/(x+30))= 2}}}

Multiply by the LCD x(x+30)

40(x+30)+40x= 2x(x+30)

40x+1200+40x=2x^2+60x

2x^2-80x+60x-1200=0
2x^2-20x-1200=0
/2
x^2-10x-600=0
(x-30)(x+20)=0
x= 30 the speed while going to airport



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