6
-13
1
7
36
To find what to add to 9.68 to get 12, subtract 9.68 from 12: 12 - 9.68 = 2.32
Any number when doubled becomes even. Thus the key part of the question is identifying a 3 digit even number that you can add 2 to to become a 4 digit number. The answer is 998. Thus to find the original number we need to do 998/2. This calculates to 499.
The number is 121/2.
1
A natural number is doubled when added to its reciprocal. Find that number!
2
7
The number is 20.
When you add a number to another number the result is their sum
7 just 7
36
33
6
36