Question

1-3+(1-9)
-13-(10-7-5)

Answer 1

1-3+(1-9)-13-(10-7-5)
1-3+(-8)-13-(-2)
-2-8-13+2
-10-11=-21

Answer 2

1-3+(1-9)
-2+1-9
-10

-13-(10-7-5)
-13-10+7+5
    -11