18/x = 4/(x - 3) + 15/(x + 3)
18 4(x+3) + 15(x-3)
=
x x^2 - 9
x^2 - 33x + 162 = 0
x1 = 27 км/ч x2 = 6 км/ч
18/x = 4/(x - 3) + 15/(x + 3)
18 4(x+3) + 15(x-3)
=
x x^2 - 9
x^2 - 33x + 162 = 0
x1 = 27 км/ч x2 = 6 км/ч