Hello!! Is this the answer you were looking for?
I swear i would love to help but im answer random question quickly cuz im in the middle of a MATH QUIZ
So hmm notice the picture below
running a segment from the right-angle perpendicular to the opposite side, gives three similar triangles, one small, a medium and a large one
now, using proportions, you can simply

and solve for "x"
Answer:
{x,y} = {8,3}
Step-by-step explanation:
// Solve equation [2] for the variable y
[2] 4y = 2x - 4
[2] y = x/2 - 1
// Plug this in for variable y in equation [1]
[1] 3x - 4•(x /2-1) = 12
[1] x = 8
// Solve equation [1] for the variable x
[1] x = 8
// By now we know this much :
x = 8
y = x/2-1
// Use the x value to solve for y
y = (/2)(8)-1 = 3