SOLUTION: a^-2-2a^-1+5=0 I have tried this problem several times and am stuck. I can tell you I put the negatives on the bottom and came up with a common demoninator but I still can not

Algebra ->  Exponents-negative-and-fractional -> SOLUTION: a^-2-2a^-1+5=0 I have tried this problem several times and am stuck. I can tell you I put the negatives on the bottom and came up with a common demoninator but I still can not       Log On


   

Question 539739: a^-2-2a^-1+5=0
I have tried this problem several times and am stuck. I can tell you I put the negatives on the bottom and came up with a common demoninator but I still can not come up with the correct answer.
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
a%5E-2-2a%5E-1%2B5=0
%281%2Fa%5E2%29-%282%2Fa%29%2B5=0
LCD = a^2
Multiply equation by LCD
1-2a%2B5a%5E2=0
5a%5E2-2a%2B1=0
Find the roots of the equation by quadratic formula

a= 5 ,b= -2 ,c= 1
b^2-4ac=
b^2-4ac= 4 - -20
b^2-4ac= -16
sqrt%28%09-16%09%29= 4i
x=%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29
x1=%28-b%2Bsqrt%28b%5E2-4ac%29%29%2F%282a%29
x1= (-(-2)+4i)/10
x1=0.2+0.4i
x2=0.2-0.4i
m.ananth@hotmail.ca