Answers

2016-08-02T07:23:26+08:00
Total time =1hr and 20 min=1 20/60= 1 1/3= 1.333hrs;

t1+t1=1.3333;
d1=d2;

t1=d1/x;
i pressume that 1okm is 10km/he;

t2=d2/10+x;
d1/x + d2/10+x=1.3333;

5/x+ 5/10+x= 1.3333;
50 +5x +5x =[10+x]x} 1.3333;
50 +10x =10x+x^2]1.3333;
50+10x=13.3333x +1.333x^2;
1.3333x^2+3.3333x-50=0;
x^2 +2.5x-37.6=0

x=[-2.5 +12.5]/2;
x=5kph


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