These two triangles are congruent by the Hypotenuse-Leg Theorem.

Answer:
[tex] y = - 2 [/tex]
Step-by-step explanation:
Given that the 2 triangles are congruent based on the Hypotenuse-leg theorem, this implies that:
[tex] x - y = x + 2 [/tex] , and [tex] 2x - y = 4x + 2y [/tex]
Using the expression, [tex] x - y = x + 2 [/tex], solve for y:
[tex] x - y - x = x + 2 - x [/tex]
[tex] - y = 2 [/tex]
[tex] y = - 2 [/tex]