Answer:
y = StartFraction 5 Over 9 EndFraction
y=5/9
Explanation:
Given:
x+6y=20
-x+3y=-15
x+6y=20. (1)
-x+3y=-15 (2)
From (1)
x=20-6y
Substitute x=20-6y into (2)
-x+3y=-15
-(20-6y)+3y = -15
-20+6y+3y = -15
9y=-15+20
9y=5
Divide both sides by 9
9y/9=5/9
y=5/9
y = StartFraction 5 Over 9 EndFraction