Considering the one-time deposit and monthly rent, the equation y=1200+400x can be used to represent y, the total cost of renting an apartment for x months. what is the amount of the deposit? a. $30 b. $400 c. $800 d. $1200 < my answer ( check this ^_^

In this item, we are given with the equation,
    y = 1200 + 400x

where y is the total amount of rent and x is the number of months. 

There are two terms in the right-hand side of the equation: 1200, and 400x. It is observed that the value of the first term is constant at 1200 while that of the second term is variable depending on the number of months. The first term therefore can be attributed as the deposited value. 

Therefore, the answer to the question is letter D.