Đáp án:
Giải thích các bước giải:
a, ($\sqrt[]{27}$ -$3\sqrt[]{12}$ + $2\sqrt[]{6}$ ):$3\sqrt[]{3}$
=($\sqrt[]{9.3}$- $3\sqrt[]{4.3}$ +$2\sqrt[]{6}$ ):$3\sqrt[]{3}$
=($3\sqrt[]{3}$ -$6\sqrt[]{3}$+ $2\sqrt[]{6}$ ):$3\sqrt[]{3}$
=1-2+$\frac{2\sqrt2}{3}$
=$\frac{2\sqrt2}{3}$ -1
b, $(\sqrt3+1)^{2}$ +($1-\sqrt3)^{2}$
=3+$2\sqrt[]{3}$ +1+1-$2\sqrt[]{3}$ +3
=8
c, $\sqrt[]{6+2\sqrt5}$ + $\sqrt[]{6-2\sqrt5}$
=$\sqrt[]{(\sqrt5 +1)^2}$ +$\sqrt[]{(\sqrt5 -1)^2}$
=$\sqrt[]{5}$ +1+$\sqrt[]{5}$-1
=$2\sqrt[]{5}$
d, $\sqrt[]{9-4\sqrt5}$ -$\sqrt[]{9+4\sqrt5}$
=$\sqrt[]{(\sqrt5 -2)^2}$ -$\sqrt[]{(\sqrt5+2)^2}$
=$\sqrt[]{5}$ -2-($\sqrt[]{5}$ +2)
=$\sqrt[]{5}$ -2-$\sqrt[]{5}$ -2
=-4
