Question

2 x
square - 4 x minus 2 equals to zero

Answer 1

Answer:

ax^2+bx+c=0

So for our problem, a=2, b=-4, and c=-2.

Now we plug those numbers into the quadratic equation.

x=[-b±(b^2–4ac)^(1/2)]/(2a)

So x=[4±({-4}^2–4*2*{-2})^(1/2)]/(2*2)

So [4±(16+16)^.5]/4=x

Then, [4±(32)^.5]/4=x

Realize that 32=16*2, and that 16^.5=4

So, [4±4*2^.5]/4=x,

Finally, 1±2^.5=x

1+2^.5=x

1–2^.5=x

Unfortunately 2^.5 is not a rational number and there for neither answer can be expressed exactly in fraction or decimal form