Answer:
-8b + 9 - 5k
Explanation:
I am assuming the blue highlighted portion is your answer, and is not a part of the initial question
(-4b + 15 - 7k) - (6 + 4b - 2k)
Combine like terms
-4b - + 4b
Negative + Positive = Negative
-4b - 4b = -8b
15 - 6 = 9
-7k - - 2k
Negative + Negative = Positive
-7k + 2k = -5k
Put them all together:
0b + 9 - 5k
Simplify
-8b + 9 - 5k
I got the same answer as you (just in a different order)