# Thread: Rational Equation to solve each cost problem

1. ## Rational Equation to solve each cost problem

You make a down payment of $22,000 and monthly payments of$1800 toward the purchase of a new house. After how many months will your average monthly cost of purchasing the house be $3000,$2500, $1500? TIA! 2. Originally Posted by eagertolearn You make a down payment of$22,000 and monthly payments of $1800 toward the purchase of a new house. After how many months will your average monthly cost of purchasing the house be$3000, $2500,$1500?

TIA!
Lets solve for case A where average monthly costs becomes $3000. You should be able to solve case B($2500) and case C($1500) similarly. Let this happens after x months. The total amount paid in those x months =$22000 + 1800*x
Now avg. monthly cost = total amount paid/total no. of months = (1800x+22000)/x = 3000;

Solve for x to get the no. of months.
I got in fraction though (18.333 months)!

3. Thank you annran!