Question

solve x^2+2x-4=0
i think i have the answer but want to b certain

Answer 1

\[x=-\sqrt{5}-1\] or
\[x=\sqrt{5}-1\]

Do you need help with how to find this?

Answer 2

i have it as 2 ans -2 can you show how you got your answer?

Answer 3

4-4*1*(-4) = 20 ==> x=[ -2+ or (-) sqrt(20)]/2 ==> x= [-2+2sqrt(5)]/2 or x= [-2-2sqrt(5)]/2

Answer 4

hence, x = -1 +sqrt(5)/2 or x =-1-sqrt(5)/2

Answer 5

the anwer is not a square root

Answer 6

\[x^2+2x-4=0\]
add 4 on both sides
\[x^2+2x=4\]
add 1 on both sides
\[x^2+2x+1=4+1\]
we added one so that we could complete the square on the left hand side
\[(x+1)^2=5\]
now take square root of both sides
\[x+1=\pm \sqrt{5}\]
now subtract one on both sides
\[x=-1 \pm \sqrt{5}\]