I am stuck on this question of my maths test.

Answer:
angle y
58 + 38 + y = 180 (angle sum property)
96 + y = 180
y = 180 - 96
y = 84
angle x
x = 29 (58/2)
(angle subtended by an arc at centre is double the arc at any point on remaining part of centre)
the values of x = 29 and y = 84