[tex] x^{2} - b^{2} -ax-ab[/tex]
[tex] a^{2} y^{2} - x^{6} [/tex]
[tex] c^{2} -6c+9-4x^{2} [/tex]
[tex]4 c^{2} +20c+25-9 a^{2} [/tex]
[tex] y^{2} x+y+y x^{2} +x+4yx+4[/tex]
[tex] c^{2} -4c+4-9 x^{2} [/tex]
[tex]3 x^{2} +2x-xy-2 y^{2} +y ^{3} -3xy ^{2} [/tex]
[tex] x^{2} +x-xy- y^{2} +y ^{3} -xy^{2}[/tex]
[tex] a^{2} x+a+a x^{2} +x+2ax+2[/tex]