SOLUTION: hello. i'm on chapter 5 section 4 problem 20. thanks for helping me can you work that problem out for me? what confuses me is i had a negative twelve for the square root, and i k

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: hello. i'm on chapter 5 section 4 problem 20. thanks for helping me can you work that problem out for me? what confuses me is i had a negative twelve for the square root, and i k      Log On


   

Question 159885This question is from textbook algebra 2
: hello. i'm on chapter 5 section 4 problem 20.
thanks for helping me
can you work that problem out for me? what confuses me is i had a negative twelve for the square root, and i know that square roots aren't suppose to be negative so then i multiplied each side by negative one, but then that left the x squared negative, and i don't know how to write that in paranthesis to be correct. I'm afraid i went wrong from there so can u please explain that and the whole problem to me?
0=x2-6x+3 (the first x is supposed to be squared)
 This question is from textbook algebra 2

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'm not quite sure of what you are trying to do. Are you trying to solve for x? If not, then what are the exact instructions?


x%5E2-6x%2B3=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=-6, and c=3


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%28-6%29+%2B-+sqrt%28+%28-6%29%5E2-4%281%29%283%29+%29%29%2F%282%281%29%29 Plug in a=1, b=-6, and c=3


x+=+%286+%2B-+sqrt%28+%28-6%29%5E2-4%281%29%283%29+%29%29%2F%282%281%29%29 Negate -6 to get 6.


x+=+%286+%2B-+sqrt%28+36-4%281%29%283%29+%29%29%2F%282%281%29%29 Square -6 to get 36.


x+=+%286+%2B-+sqrt%28+36-12+%29%29%2F%282%281%29%29 Multiply 4%281%29%283%29 to get 12


x+=+%286+%2B-+sqrt%28+24+%29%29%2F%282%281%29%29 Subtract 12 from 36 to get 24


x+=+%286+%2B-+sqrt%28+24+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%286+%2B-+2%2Asqrt%286%29%29%2F%282%29 Simplify the square root (note: If you need help with simplifying square roots, check out this solver)


x+=+%286%29%2F%282%29+%2B-+%282%2Asqrt%286%29%29%2F%282%29 Break up the fraction.


x+=+3+%2B-+sqrt%286%29 Reduce.


x+=+3%2Bsqrt%286%29 or x+=+3-sqrt%286%29 Break up the expression.


So the answers are x+=+3%2Bsqrt%286%29 or x+=+3-sqrt%286%29


which approximate to x=5.449 or x=0.551