x- y =12

x^3 - y^3 = 35028

x = 12+y

(12+y)^3   -y^3  =35028

1728+432y +36y^2 +y^3 - y^3 =35028

36y^2+432y -33300=0

y^2+12y-925=0

y = -37      y = 25

x = -25    x = 37

Ответ -25 и -37,     37 и 25