If B= A^3 / (A -2) what does 'A' equal?
Possible, but not fun, according to my cheating. It depends on why you'd need it.
Yes polynomials do tend to "look" easy to solve because they have nice round integers as coefficients... but in general solving a polynomial algebraically is not easy. For instance solving $\displaystyle x^5 - 1 = 0$ is easy, make that $\displaystyle x^5 + 2x - 1 = 0$ and we're all stumped. In fact in practice polynomials are solved by approximation in the real world. But that doesn't mean it's wrong to learn how to solve cubics!