a+b+c+d=45
Zhang Long conceded two goals.
(a-2)
Zhao Hu added two goals (b+2),
Wang Fang's ball doubled (2c),
The ball in the horse circle is reduced by half (d/2)
(a—2)=(b+2)
(b+2)=(2c)
(2c)
=(d/2)
Four equations
Four unknowns, it is possible to find four values of abcd.