Answer:
Explanation:
recall that the inside angles of a triangle add up to 180°
and also that the angle 115° is the other part of a 180° total
180=115+y
180-115 =65
then the inside angle at Y is 65°
add the three inside (interior of the triangle) angles up
180= 65 + (4k+5) + (6k+10)
180 = 65 + 10k + 15
180 = 80 + 10k
100 = 10k
10 = k
see how I did that?