I screenshot my attempt to answer the question. Did I do this correctly?

Also, no other information is given for this question and there are no attachments to the homework problem I am completing. I don't think any other information is required, since I think I solved this equation correctly, but I just wanted confirmation that I completed this question correctly. 60-Cobalt and 51-Cr isotopes release photons at specific energies when they decay, hence the 180 degree backscatter assumption in the problem (due to conservation of momentum).

# 10 IV.10 Calculate the respective energies of 1.33-MeV Co and 0.321-MeV 51Cr photons that are backscattered (at 180) incident particle scattered EK energy photon 1 + (E /mec? ) (1 - coso. For 1.33- Mev Co: Es Scattered (1.33 Mev ) photon 1+ (1.33 Mev / 0.51(MeD) ( 1-cos 180) E. scattered 0.214 Mer photon For 0. 321 - Mev 51 Cr: . Scattered = (0.321 MeV) photon 1+ (0.321 Mev/ 0.51(Me))( 1-cos 180') Escattered 0.142 Mel photon