Question

x2 − 8x − 4 = 0

Answer 1

Use the quadratic formula
\[x=\frac{-b \pm \sqrt{b^2-4(a)(c)}}{2a}\]
Put a=1, b=-8 and c=-4 into the formula and solve x

Answer 2

x1,2=(8+/-sqrt(64+16))/2
x1=4+2sqrt(5)
x2=4-2sqrt(5)

Answer 3

8+/-25sqrt 5

Answer 4

no .. look at my answer

Answer 5

since middle term has an even coefficient, it might be easier to "complete the square" via
\[x^2-8x=4\]
\[(x-4)^2=4+4^2\]
\[(x-4)^2=20\] and go from there
take the square root (don't forget the \(\pm\)) and then add 4 top both sides