I’m just gonna go with it’s 2 separate math questions
so for:2y+7x=-5
(In my answers If there is a slash between two numbers it means it is a fraction)
X= - 2y/7-5/7
Y= - 7x/2-5/2
For 5y-7x=12
X= 5y/7-12/7
Y=7x/5+12/5
Hope I could help