27^8 : 9^4
C=\(\frac{\frac{8}{9}-\frac{8}{27}-\frac{8}{81}+\frac{8}{243}}{4-\frac{4}{3}+\frac{4}{9}+\frac{4}{27}}\)
Tính
[(5*4^6*9^4-3^9*(-8)^4]/[4*2^13*3^8+2*8^4*(-27)^3]
\(\dfrac{5\cdot4^6\cdot9^4-3^9\cdot\left(-8\right)^4}{4\cdot2^{13}\cdot3^8+2\cdot8^4\cdot\left(-27\right)^3}\)
\(=\dfrac{5\cdot2^{12}\cdot3^8-3^9\cdot2^{12}}{2^{15}\cdot3^8-2^{13}\cdot3^9}\)
\(=\dfrac{2^{12}\cdot3^8\cdot\left(5-3\right)}{2^{13}\cdot3^8\left(2^2-3\right)}=\dfrac{1}{2}\cdot\dfrac{2}{1}=1\)
Điền dấu thích hợp vào chỗ chấm
9/14 ... 11/14 4/25 ... 4/23 5/6 ... 7/8 1 ... 14/15
8/9 ... 24/27 20/19 ... 20/27 8/7 ... 9/8 1 ...15/14
9/14 .<.. 11/14 4/25 .<.. 4/23 5/6 ..<. 7/8 1 ..>. 14/15
8/9 ..=. 24/27 20/19 ..>. 20/27 8/7 .>.. 9/8 1 .<..15/14
\(\dfrac{9}{14}< \dfrac{11}{14};\dfrac{8}{9}=\dfrac{24}{27}\)
\(\dfrac{4}{25}< \dfrac{4}{23};\dfrac{20}{19}>\dfrac{20}{27}\)
\(\dfrac{5}{6}< \dfrac{7}{8};\dfrac{8}{7}>\dfrac{9}{8}\)
\(1>\dfrac{14}{15};1< \dfrac{15}{14}\)
9/14 .<.. 11/14 4/25 .<.. 4/23 5/6 ..<. 7/8 1 ..>. 14/15
8/9 ..=. 24/27 20/19 ..>. 20/27 8/7 .>.. 9/8 1 .<..15/14
m x 9 / 16 = 27 / 8
4 / 9 : m = 2 / 27
M×9/16=27/8
M=27/8÷9/16
M=6
4/9÷m=2/27
M=4/9÷2/27
M=6
So sánh. : a, 3^18 và 27^4 ; b, 7^8 và 49^4 ; c, 9^16 và 27^8
a: 27^4=(3^3)^4=3^12<3^18
b: 49^4=(7^2)^4=7^8
c: 9^16=(9^2)^8=81^8>27^8
\(\dfrac{-1}{3}.\dfrac{2}{5}\)
\(\dfrac{-3}{7}.\dfrac{4}{15}\)
\(\dfrac{-9}{3}.\dfrac{15}{27}\)
\(\dfrac{-5}{6}.\)( -12 )
\(\dfrac{-12}{4}.\dfrac{8}{9}\)
\(-3.\dfrac{7}{6}\)
\(\dfrac{-15}{9}.\dfrac{27}{5}\)
\(-9.\dfrac{4}{27}\)
-2/15
-4/35
-5/3
10
-8/3
-7/2
-9
-4/3
Chúc em học giỏi
\(=\dfrac{-2}{15}\\ =\dfrac{-4}{35}\\ =-1\\ =10\\ =\dfrac{-8}{3}\\ =-7\\ =-9\\ =\dfrac{-4}{3}\)
1) 73 – (2 – 9) 2) (–45) + 27 – 8 3) 27 – 52 + (–18)
4) (–4) . (–12) 5) (–36) : 9 6) (–14) : (–7)
7) 24 : (–8) . (–15) 8) (–54) – (–6) . 5 + 9 9) (–2) . 25 + 54 : (–3)3
10) (35 – 28) . (–17 + 12)2 11) –400 : (–3 – 7)2 + 9 12) (–5)2 . (–2) + 48 : (–4)2 13) (–10) + 54 : [(–3)2 . (–4) + (14 – 17)2] 14) (–60) : [11 + (6 – 9)2] 15) –70 : {46 – [12 + 5 . (–32 : 16)2]} – 20210
22/25.(5/11-8/9)-8/9.(27/4-22/25)
\(\frac{22}{25}.\left(\frac{5}{11}-\frac{8}{9}\right)-\frac{8}{9}\left(\frac{27}{4}-\frac{22}{25}\right)\)
\(\frac{22}{25}.\left(\frac{5}{11}-\frac{8}{9}\right)-\frac{8}{9}.\left(\frac{27}{4}-\frac{22}{25}\right)=\frac{22}{25}.\frac{5}{11}-\frac{22}{25}.\frac{8}{9}-\frac{8}{9}.\frac{27}{4}+\frac{8}{9}.\frac{22}{25}=\frac{2}{5}-\frac{6}{1}=\frac{-28}{5}\)
22/25. (5/11-8/9)-8/9. (27/4-22/25)