30/(x+2) + 13/(x-2) = 3/2
60x-120 +26x +52 =3x^2 -12
3x^2 -86x +56 =0
D = 6724
x = (86-82)/6 =2/3
x = (86+82)/6=28
ответ 28 км /ч
30/(x+2) + 13/(x-2) = 3/2
60x-120 +26x +52 =3x^2 -12
3x^2 -86x +56 =0
D = 6724
x = (86-82)/6 =2/3
x = (86+82)/6=28
ответ 28 км /ч