Question

sorry, can someone please solve this for me! i keep getting a weird answer after i used the quadratic formula. solution set for the equation
-2x^2+8x-8=0
A) {-2}
B) {2}
C) {-2,2}
D) {-2, 0, 5}

Answer 1

what's your "wierd" answer?

Answer 2

or maybe im solvign ti wrong because i get a negative answer inside the radical =P

Answer 3

\[x=\frac{-8\pm \sqrt{(-8)^2-4(-2)(-8)}}{2(-2)}\]

Answer 4

that's prolly it...
you can also factor out a -2 first to simplify the equation.

Answer 5

\[\sqrt{(-8)^2-4(-2)(-8)}=64-64=0\]

Answer 6

*\[=\sqrt{64-64}=\sqrt0=0\]
the discriminant is zero

Answer 7

so \[x=\frac{-8}{-4}=2\]

Answer 8

alright, got it. thanks!