Answer: The required value of c is 36.
Step-by-step explanation: We are given to find the value of c so that the following expression becomes a perfect square trinomial :
![E=x^2-12x+c~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/p1clqa525897vbce690zfwtcf2qgkpzp6l.png)
To find the value of c, we proceed as follows :
![E\\\\=x^2-12x+c\\\\=(x^2-2* x*6+6^2)+c-6^2\\\\=(x-6)^2+c-36.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bbqafpmth2jy8v1lkshjxdsw5vl4u9uqgv.png)
So, for E to be a perfect square trinomial, we must have
![c-36=0\\\\\Righatrrow c=36.](https://img.qammunity.org/2020/formulas/mathematics/middle-school/s1itjjlb5sf3n0krm9d9ysup0eo5o9ctkv.png)
Thus, the required value of c is 36.