Bài 9:
\(a,13=\sqrt{169}< \sqrt{170}\\ b,\sqrt{6}< \sqrt{9}=3\\ c,15=\sqrt{225}< \sqrt{226}\\ d,\sqrt{12}< \sqrt{17}\left(12< 17\right)\)
Bài 10:
\(a,\left(\sqrt{7}+\sqrt{15}\right)^2=23+2\sqrt{105}\\ 7^2=49=23+26\\ 2\sqrt{105}=\sqrt{420}< \sqrt{676}=26\\ \Rightarrow\sqrt{7}+\sqrt{15}< 7\\ b,\sqrt{17}+\sqrt{5}+1>\sqrt{16}+\sqrt{4}+1=4+2+1=7=\sqrt{49}>\sqrt{45}\)
9
A 13< căn 170
B căn 6< 3
C 15 = căn 226
10
5 căn 6 > 6 căn 5
a căn 7 + căn 15 >7
b căn 17 + căn 5 +1 >căn 45
a)13^2=169<170
=>√170>13
b)3^2=9>6
=>√6<3
c)15^2=225<226
=>15<√226
d)12<17
=>√12<√17
