Решение:
........Будет 0,8х.
360 / 8 = 45км проходили вдвоем за 1 день
45-20=25км проходил второй за 1д
<span>1/6 : (1/4х-1/3)-3/8=1/40
</span><span>1/6 : (1/4х-1/3)=1/40+3/8
</span><span>1/6 : (1/4х-1/3)=1/40+15/40
</span><span>1/6 : (1/4х-1/3)=16/40
</span><span>1/6 : (1/4х-1/3)=2/5
</span><span>1/4х-1/3=1/6:2/5
</span>1/4х-1/3=1/6*5/<span>2
</span>1/4х-1/3=5/12
1/4х=5/12+1/3
1/4х=5/12+4/12
1/4х=9/12
1/4х=3/4
х=3/4:1/4
х=3/4*4/1
х=3