回答

✨ ベストアンサー ✨

(P0S+mg)L = {P0S + (M + m)g}(L - l)

(P0S+mg)L = {P0S + (M + m)g}L - {P0S + (M + m)g}l

{P0S+(M + m)g}l = {P0S + (M + m)g}L - (P0S + mg)L

{P0S+(M + m)g}l = MgL

この回答にコメントする
疑問は解決しましたか?