The answer you are looking for is (x+4)²+10.
Solution/Explanation:
Selecting the "x" term's coefficient,
It would be 8.
Now, dividing it by 2,
8/2=4.
Squaring 4,
4²=16.
So, now, since (x+4)²=x²+8x+16, you must solve for 26-16, which equals 10, which you would supplement into the equation.
So, therefore, (x+4)²+10.
I hope this has helped you. Enjoy your day.