Answer:
1st one is correct ....................
x = 8, y = 12
Step-by-step explanation:
Since the triangles are congruent, we know that the parallel sides are equal to each other.
So,
4x - 7 = 3x + 1
4x - 3x = 1 + 7
x = 8
x + y = 20
8 + y =20
y = 20 - 8
y = 12
