Question Number 45794 by Tawa1 last updated on 16/Oct/18
Answered by MJS last updated on 16/Oct/18
$${a}\ast{c}={b}\:\Rightarrow\:{b}\ast{c}^{−\mathrm{1}} ={a}\:\Rightarrow\:{c}^{−\mathrm{1}} ={b} \\ $$$${b}\ast{c}={d}\:\Rightarrow\:{d}\ast{c}^{−\mathrm{1}} ={b}\:\Rightarrow\:{c}^{−\mathrm{1}} ={b} \\ $$$${c}\ast{c}={a}\:\Rightarrow\:{a}\ast{c}^{−\mathrm{1}} ={c}\:\Rightarrow\:{c}^{−\mathrm{1}} ={b} \\ $$$${d}\ast{c}={c}\:\Rightarrow\:{c}\ast{c}^{−\mathrm{1}} ={d}\:\Rightarrow\:{c}^{−\mathrm{1}} ={b} \\ $$$$\Rightarrow\:{c}^{−\mathrm{1}} ={b} \\ $$
Commented by Tawa1 last updated on 16/Oct/18
$$\mathrm{God}\:\mathrm{bless}\:\mathrm{you}\:\mathrm{sir} \\ $$