Two variable problems

13. 2x+y=6 y=6-2x
14. 5x+y=7 y=7-5x
15. 3x+2y=8 2y=8-3x
16. 2x+5y=10 5y=10-2x

My perfect job would be a professional ping-pong player. My money would be very valuable to me. I would make $1200 a month. Just to pay for utilities it would take 45% of my money. My cell phone would cost me $72 dollars a month. Groceries would cost me 16.666 pecent of my money. Gas would also cost me 13.333 percent of my money. I'm running out of money and I still would like to put some into savings and some money for entertainment. I would spend 196 dollars a month on entertainment, then I would put 132 dollars into savings. Money is very scarce for me.