Binomial Expansion relative error

Hence find a quadratic approximation for 7-4x/(2x-1)(x+2) when |x| is small. Find the relative error in this approximation when x=0.1".
I got the quadratic approximation to be -7/2 - 13x/4 -(67x^2)/8, which is the correct answer, however I cannot get the right answer of 0.505% for the relative error. I am getting -0.484% from doing:

(-3.909+3.928)/-3.928 x 100%, where -3.909 is the measured value and -3.928 is the actual value.

Try working to a higher degree of accuracy, not just 4-figures.

ahh yeah I got the right error now, only thing is that it is a negative error, is that ok?