10 - (-9) = 19
19
10
you need 11 more.
You need to add 6 - (-9) = 6 + 9 = 15.
you need to add +9 +9-7 = +2
19
18
You need to add 18 to negative 8 to get 10.
When you add -9 and +10, you get (+) 1.
you need to add 10
19
if you mean 9/10 + 3/5 then multiply 3/5's numerator and denominator to get 6/10, which you can add to 9/10 to get 15/10, or 3/2. 1 1/2 if you need mixed numbers.