Answer:
x = 8
and y = 4
Explanation:
We have,
x + y = 12 (i)
x = 2y, (ii)
Then, putting the value of x from (ii) into (i),
x + y = 12
2y + y = 12
3y = 12
y = 12/3
y = 4
Now, since x = 2y,
x = 2(4)
x = 8
(also, x + y = 12, so x = 4 = 12, x = 12 -4, x = 8)