The question is as follows:
A formula to estimate the monthly payment, p dollars on a short-term loan is
$$ p = \frac{\frac{1}{2}ary + a}{12y}$$
where a is the amount of loan, r is the annual interest rate expressed as a decimal, and y is the length of the loan. When a is multiplied by $2$, what is the effect on p?
I tried to substitute numerical values in for the variables, and got the answer to be that p would be divided by $6$, but that is not the correct answer. Can someone explain how to answer this question? Any help will be greatly appreciated.
Hint:
reordering you have $$ p=\frac{ry+2}{24y} a $$
substitute $2a$.....