x_1, x_2, 
12+4*x_2+2*x_1
5*x_1^2+20*x_1*x_2+2*x_2^2+40*x_1+8*x_2-12
4*x_1^3+34*x_1^2*x_2+10*x_1*x_2^2+52*x_1^2+16*x_1*x_2+4*x_2^2-30*x_1-12*x_2+12
x_1^4+24*x_1^3*x_2+17*x_1^2*x_2^2+32*x_1^3+8*x_1^2*x_2+8*x_1*x_2^2-35*x_1^2-16*x_1*x_2-6*x_2^2+8*x_1+16*x_2-12
