How do you solve x^2-8x+3=0 using the quadratic formula?

1 Answer
Aug 22, 2016

x = 7.605 and x= 0.395

Explanation:

I'll show the quadratic formula down below so we can use that as a reference:
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I think it's worthwhile to mention that a is the number that has the x^2 term associated with it. Thus, it would be 1x^(2) for this question.b is the number that has the x variable associated with it and it would be -8x, and c is a number by itself. It would be 3 for this question.

Now, we just plug our values into the equation like this:

x = (- (-8) +- sqrt((-8)^(2) - 4(1)(3)))/(2(1))

x = (8 +-sqrt(64-12))/2

x = (8 +- 7.21)/2

For these type of problems, you will obtain two solutions because of the +- part. So what you want to do is add 8 and 7.21 together and divide that by 2:

x = (8+7.21)/2
x = 15.21/2= 7.605

Now, we subtract 7.21 from 8 and divide by 2:

x = (8-7.21)/2
x = 0.79/2 = 0.395

Therefore, the two possible solutions are:
x = 7.605 and x = 0.395