Si el valor de entrada es el nombre y el valor de salida es la letre con la que empieza

The sum of two numbers is 86, and their difference is 20. find the two numbers

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

It took alice 5 5/6 hours to drive to her grandparents' house for . on the way home, she ran into traffic and it took her 7 3/8 hours. how much longer did the return trip take? write your answer as a proper fraction or mixed number in simplest form. the trip home took __hours longer. ?