Answer:
B
Step-by-step explanation:
All of the choices are ways to solve x^2 - 8x = 9 except for square rooting.
A. We can factor x^2 - 8x = 9 by first making it into x^2 -8x - 9 = 0 and then factoring into: (x - 9)(x + 1) = 0.
C. We can also complete the square by adding 16 to both sides:
x^2 - 8x + 16 = 9 + 16 = 25 and then square rooting both sides from there.
D. We can finally use the quadratic formula (x = [tex]\frac{-b+\sqrt{b^2-4ac} }{2a}[/tex] or x = [tex]\frac{-b-\sqrt{b^2-4ac} }{2a}[/tex] ) to solve.
However, B will not work because you cannot easily square root (x^2 - 8x), if at all.
Thus, the answer is B.
Hope this helps!
