so quadatic equation is [tex] \frac{-b+/- \sqrt{b^2-4ac} }{2a} [/tex]=x since there are no fraction parts, the 2a part mus cancel for simplicity, assume that a=1 therefor the 2a part simplifies to 1 replace all a's with 1 [tex] \frac{-b+/- \sqrt{b^2-4(1)c} }{2(1)} [/tex]=x [tex] \frac{-b+/- \sqrt{b^2-4c} }{2} [/tex]=x -b must equal 2 times 8 since the whole thing is divided by 2 therefore b=-16 subsitue [tex] \frac{-(-16+/- \sqrt{-16^2-4c} }{2} [/tex]=x [tex] \frac{16+/- \sqrt{256-4c} }{2} [/tex]=x since the i is 1i that means that the simplified square root is equal to 2i so therefor the inside must result in -4 256-4c=-4 add 4c to both sides 256=4c-4 add 4 to both sides 260=4c divide both sides by 4 65=c
