To college friends rent an apartment. they have to pay the landlord two months rent and a $500 security deposit when they sign the lease. the total amount they pay the landlord is $2800. what is the rent for one month?

So, we'd set up this equation like this: 
2x + 500 = 2800. 
500 would be our y-intercept, x is 1 month, 2800 is the total cost, and of course we have the 2 as a slope because it's 2 months rent. 
For the first step, subtract 500 on both sides. 
You should come up with 2x = 2300. 
To find the rent for just one month, which is x, divide both sides by 2. 
x = 1150. Therefore, the rent for one month is $1150.