1) b^2+7*b+12 = (b+3)*(b+4)
2) 2*x^2-8*x+1 = 2*x^2-8*x+1
3)x^4-7*x^2-18 = (x-3)*(x+3)*(x^2+2)
4) x^4+9*x^2+18 = (x^2+3)*(x^2+6)
5)x^4+4*x^3+4*x^2-9 = (x-1)*(x+3)*(x^2+2*x+3)
6) y^8-y^4+4*y^2-4 = (y-1)*(y+1)*(y^2+2)*(y^4-y^2+2)
7) x^2+2*x-y^2+4*y-3 = -((-3)-x+y)*((-1)+x+y)
8) 8*x^2-12*x+2*x*y-y^2+4 = -(2-4*x+y)*((-2)+2*x+y)