Help me please veey much appreciated :)​

What properties allow transformation to be used as a problem solving tool

Someone this asap for a group of students attends a basketball game. * the group buys x hot dogs at the concession stand for $2 each. * the group buys y drinks at the concession stand for $3 each. the group buys 29 items at the concession stand for a total of $70. how many hot dogs did the group buy?

Use composition to determine if (x) or h(x) is the inverse of f(x) for the limited domain x2-1.