Answer:
y = 6
Explanation:
- x + 3y = 9 ( add x to both sides )
3y = 9 + x → (1)
y =
x ( multiply both sides by 3 to clear the fraction )
3y = 2x → (2)
substitute 3y = 2x into (1)
2x = 9 + x ( subtract x from both sides )
x = 9
substitute x = 9 into (1)
3y = 9 + 9 = 18 ( divide both sides by 3 )
y = 6