yes you can use that 1 equation.. P1V1/(n1T1) = P2V2/(n2T2) for ALL of your two state ideal gas law type problems. Use it in place of boyles, charles, avogadros, combined, etc laws...just like I showed you above
(1).. write down P1V1/(n1T1) = P2V2/(n2T2)
(2).. rearrange for your desired unknown
(3).. determine what is constant and what varies.. cancel the constants
(4).. plug and chug.. don't forget Temperature must be on an absolute scale.. R or K.. never °F nor °C
