How can i prove that: abs(x+y) less than or equal to abs(x) + abs (y)?

Raymond just got done jumping at super bounce trampoline center. the total cost of his session was $43.25 . he had to pay a $7 entrance fee and $1.25 for every minute he was on the trampoline. write an equation to determine the number of minutes (t) that raymond was on the trampoline.

There were 25 students who answered to a survey about sports. four-fifths of them like football. how many students like football?

Annabelle's homework is 75% it took her three hours how long should she estimate it will take her to complete her homework.