Answer:Here's the basic equation
m(d) = 10d + 20(d - 2) (the money total is the 10 dollar bills plus the 20 dollar bills (which are two less than the 10 dollars))
Explanation:
To simplify it, start by distributing the 20:
m(d) = 10d + 20d - 40
add like terms
m(d) = 30d - 40