Find the break even points of the expression $\frac{1-a+b-ab}{1-a}$

$classify\left(x^2-x^3+1-1\cdot 4\cdot x\right)$

$classify\left(x^2+1-1\cdot 4\cdot x\right)$

$classify\left(x^2-x^3-1\cdot 4\cdot x\right)$

$classify\left(3m^2-2m\cdot n+5n^2\right)$

$classify\left(x^2+1-4\cdot x\right)$

$classify\left(x^2-4\cdot x\right)$

$classify\left(-x^3\cdot y\right)$