What order do these numbers go in 6 boxes

Let the closed interval [a , b] be the domain of function f. the domain of f(x - 3) is given by (a) the open interval (a , b) (b) the closed interval [a , b] (c) the closed interval [a - 3 , b - 3] (d) the closed interval [a + 3 , b + 3]

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

Why is it so easy to buy on impulse and overspend with a credit card? what could you do to counteract this tendency?