Answer:
c: x = 80, y = 65, z = 100
Explanation:
The sum of all angles in a triangle is 180
so 40 + 60 + x = 180 and 15 + y + z = 180
40 + 60 + x = 180
100 + x = 80
x = 80
supplementary angles are equal to 180
x and z are supplementary
80 + z = 180
z = 100
15 + 100 + y = 180
115 + y = 180
y = 65