Question 192832
(3-2sqrt12)^2

(3-2sqrt12)  (3-2sqrt12)

9-12sqrt12+4*12

9+48-12sqrt(4*3)

57-12*2sqrt3

57-24sqrt3

check
57-24sqrt3=15.43
(3-2sqrt12)^2=15.43  ok

things  to  know   (x+1)^2=(x+1)(x+1)

(sqrt 3)^2=3

or  (sqrt9)^2=  3^2=9

sqrt(300)=sqrt(3*100)=sqrt3*sqrt100=10sqrt3