The answer is C. If you have any questions then leave a comment. Good luck!
I assume the answer is 1/4
let y = x^2
4y^2 -21y + 20 = 0
solve for y
then substitute back in to get x
691/1000 is already in its simplest form, for 691 is a prime number and it cannot be reduced by any number other than 1 and 691. (and 1000 is not divisible by 691 also)
691/1000 in its simplest form is 691/100~
