Q: I needed a fard bath. i did not know until i want to work that i needed a fard bath. Can i pray my salah?

A: In a state of major impurity one cannot perform any salah. You have to have a bath and perform your salah, you would also have to do qadha of your missed salah, and those salah you performed in the state of impurity (junub).

Allah Certainly Knows Best.