Help please x

Explain how you can use the associative property to evaluate (7x50)x4.

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?

Identify the initial amount a and the growth factor b in the exponential function. a(x)=680*4.3^x