Question

SO SÁNH     \(\sqrt{12}+\sqrt{20}+\sqrt{30}+\sqrt{42}\) VÀ 20

Answer 1

\(\sqrt{12}<\sqrt{12,25}=3,5\)

\(\sqrt{20}<\sqrt{20,25}=4,5\)

\(\sqrt{30}<\sqrt{30,25}=5,5\)

\(\sqrt{42}<\sqrt{42,25}=6,5\)

Suy ra:\(\sqrt{12}+\sqrt{20}+\sqrt{30}+\sqrt{42}\)<3,5+4,5+5,5+6,5=20

Vậy biểu thức <20

Answer 2

\(\sqrt{12}+\sqrt{20}+\sqrt{30}+\sqrt{42}