Answer:
y = 8
Explanation:
1/3x + 1/4y = 1.....lets multiply this by 12 to get rid of the fractions
12(1/3x + 1/4y) = 1(12)
4x + 3y = 12
now...lets begin
4x + 3y = 12
2x - 3y = -30
-------------------add
6x = - 18
x = -18/6
x = -3
2x - 3y = -30
2(-3) - 3y = -30
-6 - 3y = -30
-3y = -30 + 6
-3y = - 24
y = -24/-3
y = 8
lets check it..
1/3x + 1/4y = 1
1/3(-3) + 1/4(8) = 1
-1 + 2 = 1
1 = 1 (correct)......it checks out
so y = 8 <====