Question

7a+(8b) +(-15a)+9b + (-4c)+8=

Answer 1

7a+(8b) +(-15a)+9b + (-4c)+8

7a+8b-15a+9b-4c+8 ( changing some of the symbols)

7a-15a+8b+9b-4c+8

=-8a+17b-4c+8

Answer: -8a+17b-4c+8

Answer 2

-8a+17b-4c+8

steps:
when there is a "+" in front of the parenthesis the expression remains the same.

7a+8b-15a+9b-4c+8

Collect the like terms

7a+8b-15a+9b-4c+8

7a and 15a
8b and 9b

15a-7a= -8a
9b+8b= 17b

Final answer:

-8a+17b-4c+8