Given the description "The sum of a number and three is five", you need to remember the following:
- A Sum is the result of an Addition.
-The verb "is" indicates that it is an equation and, therefore, you must use this sign:
![=](https://img.qammunity.org/2023/formulas/mathematics/high-school/g7nzfjlszznuiu02vmbisphbdcxksvsh5w.png)
Let be "x" the unknown number.
"The sum of a number and three" can be represented with this expression:
![x+3](https://img.qammunity.org/2023/formulas/mathematics/high-school/8qhja03oysgzd16fx7m4wbwfiri3d6nie2.png)
Therefore, the equation is:
![x+3=5](https://img.qammunity.org/2023/formulas/mathematics/high-school/eqzn7u3z9xeiclvr868kg25k0fkefrrir8.png)
In order to find the value of "x", you need to apply the Subtraction Property of Equality by subtracting 3 from both sides of the equation:
![\begin{gathered} x+3-(3)=5-(3) \\ x=2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/lgeext8p001p39oo0w4juuqn6nwvxptr2u.png)
Hence, the answer is: The number is 2.