Contact us
Choose a category below so we can get back to you as quickly as possible.
6x+7y=20,① 7x+6y=19② ①+②得 13x+13y=39 x+y=3③ ①-6③得 y=2 ②-6③得 x=1
We and our partners use cookies and other technologies to analyze traffic and optimize your experience. View more info and control your cookies settings at any time in our Cookies Policy.