It's actually easier than it seems. if the tax is paid in equal payments every month and the total throughout a year (12 months) is $2,820, you have to find out how much they pay every month so divide the total by the number of months 2,820/12=235 they pay $235 in taxes every month to find out the total of the taxes and the house payment, just add the monthly tax and the monthly house payment. 235+752 and your answer is the sum