Question 561727
Let's say her hair cut costs h dollars

the perm is 2h (twice h)
77=2h+h+5 because the amount of money she needs 77 is equal to the cost of the perm, plus the haircut plus the lunch
combine like terms
77=3h+5
subtract 5 from both sides
72=3h
divide both sides by 3
24=h
haircut=24, perm 2h=2*24=48, lunch 5