10
You need to add 6 - (-9) = 6 + 9 = 15.
you need to add +9 +9-7 = +2
you have thirteen, this is because you do... 9+4 because you took away 4, so you need to add it back on. and as you add 1 and then take 1 away that equals zero. so all you need to do is 9+4=13
To find what you need to add to -7 to get 9, you can set up the equation: -7 + x = 9. Solving for x gives you x = 9 + 7, which simplifies to x = 16. Therefore, you need to add 16 to -7 to get 9.
add 9 add 1 subtract 20 add 9 add 1
-8
It is: -9+16 = 7
10 - (-9) = 19
-9 + 11 = 2
- 8 + 17 = 9 =========
Well, darling, the common denominator for 1/3 and 4/9 is 9. You see, to add or subtract fractions, you need a common denominator, and in this case, multiplying 3 by 3 gives you 9. So, there you have it, simple math for a simple question.
We know that a half is 1/2 as a fraction, but we can multiply the numerator and denominator by 9 and 1/2 is 9/18. The least number of ninths we can add is 1. So we add 1/9 + 9/18 which is 2/18+9/18 or 11/18. We can write this as (11/2)/9 or 5.5/9 which is 5.5 ninths.