Answer:
D.
![(x-3)^2=34](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9ywyjurv4djeyp2k4wzk1rmu11xpq9tr4b.png)
Explanation:
Its looks like they have complete the square for the given equation.
So let's do that.
![2x^2-12x-50=0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bkvuiv3wkffmkyfpwki1gmkinxwisk0uq6.png)
I see all of my terms are even so I can easily divide each of them by 2.
I'm going to divide both sides by 2:
![x^2-6x-25=0](https://img.qammunity.org/2020/formulas/mathematics/middle-school/903wxn1xpcfw9uum1xh7dlq8jd3uxfzlhu.png)
The first step in completing the square is to make sure the coefficient of
is 1 so we can use this easy formula:
.
So I see in place of k I have -6.
I'm going to add
on both sides.
![x^2-6x+((-6)/(2))^2-25=((-6)/(2))^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/5zyx1khifgnbqrdt3pt457t4p8qjhcw4zx.png)
See these first three terms here can be written using the mentioned formula:
![(x+(-6)/(2))^2-25=(-(-6)/(2))^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/dhhivq3uipp72hj9ujsfro0i4t38ajb0cz.png)
Let's simplify a bit:
![(x+(-3))^2-25=(-3)^2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mav6uubv03t4bsqbmbn1g9rjbedxhwji4s.png)
![(x-3)^2-25=9](https://img.qammunity.org/2020/formulas/mathematics/middle-school/nec3ov5w0h19yuc6fjrryyrj0mt5tg69e9.png)
Add 25 on both sides:
![(x-3)^2=9+25](https://img.qammunity.org/2020/formulas/mathematics/middle-school/h41l5sj53tcz9fzq5eq45tklgocgnxadmk.png)
![(x-3)^2=34](https://img.qammunity.org/2020/formulas/mathematics/middle-school/9ywyjurv4djeyp2k4wzk1rmu11xpq9tr4b.png)