Angie and Kenny play online video games. Angie buys 2 software packages and 3 months of gameplay. Kenny buys 2 software packages and 2 months of gameplay. Each software package costs $35. Of their total cost is $210, what is the cost of one month of gameplay?

I believe not 100% on this one that the answer is $14 for the cost of one month of gameplay. How I came up with that is answer is that if you add all the softwares they brought which is 4 and times that by $35. $35*4 = 140. Then subtract 210-140=70. Then you divide that by month of gameplay which will be 70/5=14. That's how i came up with $14