Answer:
The 25th Amendment deals with vacancy in the offices of president and vicepresident. So, it was necessary to pass it to guarantee a constitutional succession in case a president could not discharge his duties and powers. It was first applied in 1973, following Spiro Agnew´s resignation as vicepresident. President Richard Nixon nominated Gerald Ford. Then, it was invocated again a year later; following Nixon´s resignation, Gerald Ford was sworn in as president. He later nominated Nelson Rockefeller as vicepresident by using his powers given to him by the 25th Amendment.
Step-by-step explanation: