\(\sqrt{289}+\sqrt{169}=?\)
Đề bài: Tách:
a) \(\sqrt{16}+\sqrt{1}-3\sqrt{9}\)
b)\(\sqrt{\dfrac{4}{9}}-\sqrt{25}+\sqrt{100}\)
c) \(2\sqrt{169}+3\sqrt{196}-2\sqrt{289}\)
a) \(\sqrt{16}+\sqrt{1}-3\sqrt{9}=4+1-3.3=-4\)
b) \(\sqrt{\dfrac{4}{9}}-\sqrt{25}+\sqrt{100}=\dfrac{2}{3}-5+10=\dfrac{17}{3}\)
c) \(2\sqrt{169}+3\sqrt{196}-2\sqrt{289}\)
= \(2.13+3.14-2.17=34\)
\(\sqrt{16}.\sqrt{25}+\sqrt{169}:\sqrt{49}\)
\(=4\cdot5+13:7=20+\dfrac{13}{7}=\dfrac{153}{7}\)
tính
a, \(\sqrt{169}\) - \(\sqrt{225}\)
b \(\dfrac{\sqrt{144}}{9}\)
c \(\sqrt{18}\) \(\div\) \(\sqrt{2}\)
a: \(\sqrt{169}-\sqrt{225}\)
\(=\sqrt{13^2}-\sqrt{15^2}\)
=13-15
=-2
b: \(\dfrac{\sqrt{144}}{9}\)
\(=\dfrac{\sqrt{12^2}}{9}\)
\(=\dfrac{12}{9}=\dfrac{4}{3}\)
c: \(\sqrt{18}:\sqrt{2}=\sqrt{\dfrac{18}{2}}=\sqrt{9}=3\)
tinh va so sanh:
a:\(\sqrt{9\cdot4}\)va \(\sqrt{9}\cdot\sqrt{4}\)
b:\(\sqrt{169-144}\)va \(\sqrt{169}-\sqrt{144}\)
a)\(\sqrt{9.4}=\sqrt{36}=6;\sqrt{9}.\sqrt{4}=3.2=6\Rightarrow\sqrt{9.4}=\sqrt{9}.\sqrt{4}\)
b)\(\sqrt{169-144}=\sqrt{25}=5;\sqrt{169}-\sqrt{144}=13-12=1\Rightarrow\sqrt{169-144}>\sqrt{169}-\sqrt{144}\)
tra loi ho mik lun di mai ik hoc roi !chut chut chuit chut
tính
a) \(\sqrt{16}.\sqrt{25}+\sqrt{196}:\sqrt{49}\)
b) 36 : \(\sqrt{2.3^2.18}-\sqrt{169}\)
c) \(\sqrt{\sqrt{81}}\)
d) \(\sqrt{3^2+4^2}\)
a: \(=4\cdot5+14:7\)
=20+2
=22
rút gọn \(\sqrt{\frac{289+4\sqrt[]{72}}{16}}+\sqrt{\frac{129}{16}+\sqrt{2}}\)
\(\sqrt{\frac{289+4\sqrt{72}}{16}}+\sqrt{\frac{129}{16}+\sqrt{2}}\)
\(=\sqrt{\frac{288+2\times12\sqrt{2}+1}{4^2}}+\sqrt{\frac{128+2\sqrt{12}+1}{4^2}}\)
\(=\sqrt{\frac{\left(\sqrt{288}+1\right)^2}{4^2}}+\sqrt{\frac{\left(\sqrt{128}+1\right)^2}{4^2}}\)
\(=\frac{\sqrt{288}+1}{4}+\frac{\sqrt{128}+1}{4}\)
\(=\frac{12\sqrt{2}+8\sqrt{2}+2}{4}\)
\(=\frac{1+10\sqrt{2}}{2}\)
\(36:\sqrt{2.3^2.18}-\sqrt{169}\)
\(36:\sqrt{2.3^2.18}-\sqrt{169}\)
<=> 36 : \(\sqrt{324}-\sqrt{169}\)
<=> 36 : 18-13
<=> 2-13
=> -11
Bạn tự kết luận nhé !
e,\(\sqrt{\dfrac{9}{169}}\)
f,\(\sqrt{1\dfrac{9}{16}}\)
g,\(\dfrac{\sqrt{2300}}{\sqrt{23}}\)
h,\(\dfrac{\sqrt{12,5}}{\sqrt{0,5}}\)
\(e,\sqrt{\dfrac{9}{169}}=\dfrac{\sqrt{9}}{\sqrt{169}}=\dfrac{\sqrt{3^2}}{\sqrt{13^2}}=\dfrac{3}{13}\)
\(f,\sqrt{1\dfrac{9}{16}}=\sqrt{\dfrac{25}{16}}=\dfrac{\sqrt{25}}{\sqrt{16}}=\dfrac{\sqrt{5^2}}{\sqrt{4^2}}=\dfrac{5}{4}\)
\(g,\dfrac{\sqrt{2300}}{\sqrt{23}}=\sqrt{\dfrac{2300}{23}}=\sqrt{100}=\sqrt{10^2}=10\)
\(h,\dfrac{\sqrt{12,5}}{\sqrt{0,5}}=\sqrt{\dfrac{12,5}{0,5}}=\sqrt{25}=\sqrt{5^2}=5\)
e, \(\sqrt{\dfrac{9}{169}}\)
\(=\sqrt{\dfrac{3^2}{13^2}}\)
\(=\dfrac{3}{13}\)
f, \(\sqrt{1\dfrac{9}{16}}\)
\(=\sqrt{\dfrac{25}{16}}\)
\(=\sqrt{\dfrac{5^2}{4^2}}\)
\(=\dfrac{5}{4}\)
g, \(\dfrac{\sqrt{2300}}{\sqrt{23}}\)
\(=\dfrac{10\sqrt{23}}{\sqrt{23}}\)
\(=10\)
h, \(\dfrac{\sqrt{12,5}}{\sqrt{0,5}}\)
\(=\dfrac{\dfrac{5\sqrt{2}}{2}}{\dfrac{\sqrt{2}}{2}}\)
\(=\dfrac{\dfrac{5\sqrt{2}}{2}\cdot2}{\sqrt{2}}\)
\(=\dfrac{5\sqrt{2}}{\sqrt{2}}=5\)