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

1. anonymous

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

2. anonymous

i will write it out if you like

3. anonymous

Okay yeah that might help.

4. anonymous

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

5. anonymous

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.

6. anonymous

of course you should have the 'plus or minus"