These triangles are congruent, it means all sides are equal.
We equate the sides that are equal and we get this two equations:
x = y + 1 -------------- (1)
x + 3 = 3y -------------(2)
Sub (1) into (2)
(y + 1) + 3 = 3y
y + 1 + 3 = 3y
3y - y = 3 + 1
2y = 4
y = 2 -------------- sub back into (1)
x = y + 1
x = 2 + 1
x = 3
Ans: x = 3, y = 2