Hello, I'm not sure how to do this but we have to consider a bare slab by assuming

Can someone help me and do step by step without skipping any steps?

- The slab is a purely-absorbing media with a=1.25cm1, - It is exposed to an incident neutron flux of 1.01012cm2sneutrons on the left-hand side of the slab that is normal to the slab's surface, and - The slab thickness is a=2.5cm a. Solve for the analytical solution for the flux distribution in the slab