The given statement is,
To solve
![x^2+4x=7](https://img.qammunity.org/2023/formulas/mathematics/college/gyd1i34l4ms66bgnrf46zwsp0qk1bfty4m.png)
by completing the square add ______ ono both sides of the equation.
To fill the blank:
We know that the identity,
![x^2+2xy+y^2=(x+y)^2](https://img.qammunity.org/2023/formulas/mathematics/college/wxxi97rn62hs99ljrdgji3dhk5qbxrcfzd.png)
Comparing the equating terms as follows,
![\begin{gathered} 2xy=4x \\ y=2 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/jfj9p67x8yevz20kbvuwjqpnhuao3pjwmu.png)
Then, add on both sides of the equation by,
![2^2](https://img.qammunity.org/2023/formulas/mathematics/high-school/kz223c7itc97kapr2sr5qz6eznmewvu5mh.png)
Hence, the answer is,
![2^2\text{ (or) 4}](https://img.qammunity.org/2023/formulas/mathematics/college/6ypte5kunsga1fmec6itnw0iz9049affgu.png)