((4/9)^2*(-9/16)^1*(-1)^19)/((4/25)^2*(-25/144)^2*(-49/144)^2)
tính ((4/9)^2*(-9/16)^1*(-1)^19)/((4/25)^2*(-25/144)^2*(-49/144)^2)
HELP ME!!!
\(\frac{\left(\frac{4}{9}\right)^2\cdot\left(\frac{-9}{16}\right)\cdot\left(-1\right)^{19}}{\left(\frac{4}{25}\right)^2\cdot\left(\frac{-25}{144}\right)^2\cdot\left(\frac{-49}{144}\right)^2}\)tính
D=(4/49)^2*(-49/16)*(-1)^10/(4/25)^2*(-25/144)^2:(-49/144)^2
Tính a):\(\frac{\left(\frac{4}{9}\right)^2.\left(-\frac{9}{16}\right).\left(-1\right)^{19}}{\left(\frac{4}{25}\right)^2.\left(-\frac{25}{144}\right)^2.\left(-\frac{49}{144}\right)^2}\)
b)\(\frac{\left(\frac{2}{3}\right)^3.\left(-\frac{3}{4}\right)^2.\left(-1\right)^{2003}}{\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
2) . Viết thành dạng lũy thừa vơi số mũ lớn hơn 1 các số sau đây 1).8. 2).25 3).4 4).49 5).81 6).36 7).100 8).121 9).144 10).169 11).27 12).125 13).1000 14).32 15).243 16).343 17).216 18).64 19).225 20).128
1: 8=2^3
2: 25=5^2
3: 4=2^2
4: 49=7^2
5: 81=9^2
6: 36=6^2
7: 100=10^2
8: 121=11^2
9: 144=12^2
10: 169=13^2
11: 27=3^3
12: 125=5^3
13: 1000=10^3
14: 32=2^5
15: 243=3^5
16: 343=7^3
17: 216=6^3
18: 64=4^3
19: 225=15^2
20: 128=2^7
tính
a) \(\left(\frac{4}{9}\right)^2.\left(\frac{-9}{16}\right).\left(-1\right)^{19}\)/\(\left(\frac{4}{25}\right)^2.\left(\frac{-25}{144}\right)^2.\left(\frac{-49}{144}\right)^2\) b) \(\frac{10^4.81-16.15^2}{4^4.675}\)
Tính nhanh tổng a,1+4+9+16+25+....+144+169. b,1+2+4+8+16+32+........+256+512+1024
cho P=1/4+1/9+1/16+1/25+.....+1/121+1/144.Chứng tỏ rằng P <2/3
\(P=\frac{1}{4}+\frac{1}{9}+\frac{1}{16}+\frac{1}{25}+...+\frac{1}{121}+\frac{1}{144}\)
\(\Rightarrow P=\frac{1}{4}+\frac{1}{3^2}+\frac{1}{4^2}+\frac{1}{5^2}+...+\frac{1}{11^2}+\frac{1}{12^2}\)
Ta có : \(P< \frac{1}{4}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{10.11}+\frac{1}{11.12}\)
\(\Rightarrow P< \frac{1}{4}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}\)
\(\Rightarrow P< \frac{1}{4}+\frac{1}{2}-\frac{1}{12}\)
\(\Rightarrow P< \frac{2}{3}\left(đpcm\right)\)
\(P=\frac{1}{4}+\frac{1}{9}+\frac{1}{16}+\frac{1}{25}+...+\frac{1}{121}+\frac{1}{144}\)
\(P=\frac{1}{4}+\frac{1}{3^2}+\frac{1}{4^2}+\frac{1}{5^2}+...+\frac{1}{11^2}+\frac{1}{12^2}\)
Có : \(P< \frac{1}{4}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+...+\frac{1}{10.11}+\frac{1}{11.12}\)
\(\Rightarrow P< \frac{1}{4}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}\)
\(\Rightarrow P< \frac{1}{4}=\frac{1}{2}-\frac{1}{12}\)
\(\Rightarrow P< \frac{2}{3}\)( đpcm )
dpcm là gì bạn
Tính nhanh:
1+2+4+8+16+32+.......+256+512+1024
b,1+4+9+16+25+........+144+169
a, 1+2+4+8+16+32+...+256+512+1024
= 20+21+22+23+24+25+...+28+29+210
= 1 + 2 + 22+3+4+5+...+8+9+10
= 3+254
a lấy 2+8 + 4+16+......
b lấy 1+9+4+16+...
Chị Hà Anh ,hồi lớp 5 chưa học lũy thừa nên bây giờ lên lớp 6 mới hiểu dù sớm hay muộn cũng cảm ơn chị nhiều