Hi!

I am totally new to measure theory, so bear in mind that all concepts like $\displaystyle \sigma-algebra $ and $\displaystyle contents $ are new for me.

Problem:

Suppose $\displaystyle A$ is an algebra of subsets on $\displaystyle X$ and $\displaystyle \mu $ and $\displaystyle \nu $ are two contents on $\displaystyle A$ such that $\displaystyle \mu \leq \nu $ and $\displaystyle \mu(X) = \nu(X) < \infty $. Prove that $\displaystyle \mu = \nu $.

I´m not sure how to start.