Подстановка условия
[src](((x/(a*b + 1))*y)/(b*(c*b + 1)))/(1 - (x/(a*b + 1))*y/b*(c*b + 1)) при a = -3
(((x/(a*b + 1))*y)/(b*(c*b + 1)))/(1 - (x/(a*b + 1))*y/b*(c*b + 1))
1−ab+1b1xybc+11b(bc+1)1yab+1x (((x/((-3)*b + 1))*y)/(b*(c*b + 1)))/(1 - (x/((-3)*b + 1))*y/b*(c*b + 1))
1−(−3)b+1b1xybc+11b(bc+1)1y(−3)b+1x (((x/(-3*b + 1))*y)/(b*(c*b + 1)))/(1 - (x/(-3*b + 1))*y/b*(c*b + 1))
1−−3b+1b1xybc+11b(bc+1)1y−3b+1x x*y/(b*(1 - 3*b)*(1 + b*c)*(1 - x*y/(b*(1 - 3*b)*(1 + b*c))))
b(1−b(−3b+1)(bc+1)xy)(−3b+1)(bc+1)xy