13.1 - 20.2 + 9 - ( - 38.5)
to solve this, remember:
- a minus before a parenthesis, change the sign of the number within the parenthesis
So, knowing that:
13.1 - 20.2 + 9 - ( - 38.5)
13.1-20.2+9 + (+38.5) (the minus change, and the sign of the number inside, change too)
now, we can plus the positive numbers, (13.1+9+38.5 = 60.6)
and finally, we have=
13.1-20.2+9+38.5
60.6-20.2= 40.4
So the answer is: 40.4