Question

Solve using quadratic formula:
10x^2+10x=-3
I got my answer as -10+/- i(sq.root) 5
---------
10
is that right?

Answer 1

\[10x^2+10x+3=0\]
\[a=10,b=10,c=3\]
ok i think you forgot to divide -10 also. it should be \[\frac{-5+\sqrt{5}i}{10}\]

Answer 2

i will write it out if you like

Answer 3

Okay yeah that might help.

Answer 4

\[x=\frac{-10+\sqrt{10^2-4\times 10 \times 3}}{2\times 10}\]
\[=\frac{-10+\sqrt{100-120}}{20}\]
\[=\frac{-10+\sqrt{-20}}{20}\]

Answer 5

so far so good.
\[=\frac{-10+\sqrt{4\times 5\times -1}}{20}\]
\[=\frac{-10+2\sqrt{5}i}{20}\]
\[=\frac{2(-5+\sqrt{5}i}{20})\]
\[=\frac{-5+\sqrt{5}i}{10}\]
think this is right.

Answer 6

of course you should have the 'plus or minus"