Answer:
a = 9
Explanation:
The given trinomial is :
![x^2-6x+\_\_\__](https://img.qammunity.org/2022/formulas/mathematics/college/wu4htg24ac0h9mx5y29oeb0kqxuhkjf2af.png)
let the blank is a.
So, we need to find the value of a so that it results in a perfect square trinomial.
We know that,
![(m-n)^2=m^2-2mn+n^2](https://img.qammunity.org/2022/formulas/mathematics/college/43ghl1cazl6lznxqg29klhp6b9rtfvaxlb.png)
So,
![x^2-6x+a=x^2-2(1)(3)+3^2\\=(x-3)^2](https://img.qammunity.org/2022/formulas/mathematics/college/kbh9qjc9bmzcx534vblzd0u2poouk3ta4o.png)
So, the value of a is 9. If a is 9, then only it would be a perfect square trinomial.