Answer:
k = 10
Explanation:
The exterior angle of a triangle is equal to the sum of the opposite interior angles
115 = (4k+5) + (6k+10)
Combine like terms
115 = 10k+15
Subtract 15 from each side
115-15 = 10k +15-15
100 = 10k
Divide by 10
100/10 = 10k/10
10 =k