v2u-4u2+2vu-u= please help me how do I calculate
* ^ means "to the power of"
You want to start by finding the variable/variables that go into every single term.
The common term in this example is u (it cannot be v because the term 4u^2 and u do not contain a v variable.)
u(v^2 - 4u + 2v - 1) is your answer. You can multiply it out to check your answer.