-x2+4xy
-8x2+6xy
2a2+3ab
23x+32y
ax+ay+bx+by
2x2+6xy-5x-3y+2
132x2+127x+30
x2+5x-24
49x2+7x-72
x2-8x+16
9x2+84x+196
x2-y2
49m2-121n2
36m2-169n2
121x2100-144y2169
147a2+84a+12
40x3+35x2-90x
x2+9y2+6xy-2x-6y+1
3x3-31x2+32x+36
3x2-3x+6
2x2-8x-58
31x2-38x-1