I believe that you are talking about simultaneous equations? Then in that case, using the elimination method(Singapore syllabus person):
-7x+y=-2 —(1)
x-3y=7–(2)
(1)x3:
3(-7x+y)=3(-2)
-21x+3y=-6 —(3)
(2)+(3):
x-3y-21x+3y=7-6
-20x=1
x =-1/20
Substitute x=-1/20 into (2)
-1/20-3y=7
151/20=3y
y=-2.35
You could also use the graphical method and find the intersection for your x and y.
