Now we know: `(P_1\ \ V_1)/T_1=(P_2\ \ V_2)/T_2`
and we know Boyles `=` Temperature constant
If we choose ONE for the value of `T`
NOTE: It doesn't really matter what value you choose they will cancel each other out being the same.
`(P_1\ \ V_1)/1=(P_2\ \ V_2)/1`
is the same as
`P_1\ \ V_1=P_2\ \ V_2`
This is Boyles law