Just use all the ways -36 can be written as the product of two integer factors: If k is a NON-NEGATIVE integer, then these 5 are the only ways(y+1)(y-36) = y²-35x-36 k=35 (y+2)(y-18) = y²-16x-36 k=16 (y+3)(y-12) = y²-9x-36 k=9 (y+4)(y-9) = y²-5x-36 k=5 (y+6)(y-6) = y²-0x-36 k=0 If k is a NEGATIVE integer, then these 4 are the only ways (y-1)(y+36) = y²+35x-36 k=-35 (y-2)(y+18) = y²+16x-36 k=-16 (y-3)(y+12) = y²+9x-36 k=-9 (y-4)(y+9) = y²+5x-36 k=-5 Edwin