we can write the sum of two numbers like this:
![x+y](https://img.qammunity.org/2023/formulas/mathematics/high-school/16pprbicmev6bx7plee8vpwduacvbqsoix.png)
and their difference like this:
![x-y](https://img.qammunity.org/2023/formulas/mathematics/high-school/gmryb6ino2q0iyx4iwcame5dm6fqgqja8a.png)
then,in this case, we have the following system of equations:
![\begin{gathered} x+y=751 \\ x-y=255 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/zr4svkqog6wufh7qhlx83c587tl169e5wc.png)
If we add both of them together we get the following:
![\begin{gathered} x+y=751 \\ x-y=255 \\ -------- \\ 2x=1006 \\ \Rightarrow x=(1006)/(2)=503 \\ x=503 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/wevngexlyar4eueiyfhbsgjsch4var7klz.png)
now that we have the value of x, we can use it on any equation to find the value of y:
![\begin{gathered} 503+y=751 \\ \Rightarrow y=751-503=248 \\ y=248 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/dn07ouumoivh2bcdzud8huotbiwb7ftffe.png)
therefore, x = 503 and y = 248