Đáp án:
Giải thích các bước giải:
8) $2\sqrt[]{32}+4\sqrt[]{8}-5\sqrt[]{18}$
=$2.\sqrt[]{16}.\sqrt[]{2}+4.\sqrt[]{4}.\sqrt[]{2}-5.\sqrt[]{9}.\sqrt[]{2}$
=$2.4\sqrt[]{2}+4.2.\sqrt[]{2}-5.3.\sqrt[]{2}$
=$(8+8-15)\sqrt[]{2}$
=$\sqrt[]{2}$
9) $3\sqrt[]{20}-2\sqrt[]{45}+4\sqrt[]{5}$
=$3.\sqrt[]{4}.\sqrt[]{5}-2.\sqrt[]{9}.\sqrt[]{5}+4\sqrt[]{5}$
=$(3.2-2.3+4)\sqrt[]{5}$
=$4\sqrt[]{5}$
10) $2\sqrt[]{24}-2\sqrt[]{54}+3\sqrt[]{6}-\sqrt[]{150}$
=$2.\sqrt[]{4}.\sqrt[]{6}-2.\sqrt[]{9}.\sqrt[]{6}+3\sqrt[]{6}-\sqrt[]{25}.\sqrt[]{6}$
=$(2.2-2.3+3-5)\sqrt[]{6}$
=$-4\sqrt[]{6}$
11) $2\sqrt[]{18}-7\sqrt[]{2}+\sqrt[]{162}$
=$2\sqrt[]{9}.\sqrt[]{2}-7\sqrt[]{2}+\sqrt[]{81}.\sqrt[]{2}$
=$(2.3-7+9)\sqrt[]{2}$
=$8\sqrt[]{2}$