Question

Use quadratic formula to solve:

5x^2-10x+6=0

Answer 1

so, what don't you know abouth the formula? You have

a = 5
b = -10
c = 6

Now just plug them into the formula.

Answer 2

I got the answer 10 plus or minus square root of -2 equals 0....not sure if that's the final answer or not

Answer 3

You can always use wolframalpha.com to verify your work. For example,

http://www.wolframalpha.com/input/?i=5x^2-10x%2B6%3D0

You got 10±√-2

That is clearly wrong. The formula states

x = [-b±√(b^2-4ac)]/2a
= [10±√(100-120)]/10
= (10±√-20)/10
= (10±2√-5)/10
= 1±√-5/5
= 1 ± 1/√5 i

I expect that you can now find your mistake(s)

At the very least you cannot say 10±√-2 = 0