Question

Solve the equation below for 'x' using any method.
x^2=8x-35

A) 4 +/- sqrt 19
B)5
C) 3 +/- 5i
D)4 +/- i sqrt(19)

I picked D. I used the quadtratic equation

Answer 1

\[x^2=8x-35\]
If we use the quadratic, we need to put it in the form \[ax^2 + bx + c = 0\]
\[x^2-8x+35 = 0\]\[a=1,\ b=-8,\ c=35\]
\[x = \frac{-b\pm\sqrt{b^2-4ac}}{2a}\]\[x=\frac{-(-8)\pm\sqrt{(-8)^2-4(1)(35)}}{2(1)} = \frac{8\pm\sqrt{64-140}}{2}=\frac{8\pm\sqrt{-76}}{2}\]\[=4\pm i\sqrt{19}\]
Looks like you got it right.

Answer 2

@whpalmer4 thanks so much for confirming my answer!!