Rationalise the denimination of 12-5 root 3 divide by root 3

to rationalise the denominator u times the numerator and denominator by the denominator so

(12-5√3) / √3 times by √3/√3 which is √12 (12-5√3) divided by √3 (√3) so now just times the brackets out making 12√3 - (5x3) - because √3 x √3 is 3 - divided by 3 - for the same reason

so the answer is (12√3-15) / 3 which is 4√3-5