(3/7)5.(7/3)-1.(5/3)6:(343/625)-2= ?
b) (3/7)5 x (7/3)-1 x (5/3)6 : (343/625)-2
( 3/7 ) 5 x ( 7/3 ) - 1 x ( 5/3 )6 : ( 343/652) - 2
= ( 3/7 x 7/3 ) + 5 - 1 x ( 5/3 : 343/652 ) - 2
= 1 + 5 - 1 x 2 - 1715/1956
= 6 - 2 - 1715/1956
=4 - 1715/1956
= 6109/1715
bn ê, đề là j vậy,sao mk đọc mà ko hỉu
a. 12^3:(3^ -4.64)
b. (3/7)^5.(7/3)^ -1.(5/3)^6:(343/625)^ -2
c. 5^4.125.(2,5)^ -5 . 0,04
a) 123 / ( 3-4,64 )
= 1 728 / ~ 0,0 061
= ~ 283 278, 6 885
b) \(\left(\frac{3}{7}\right)^5\cdot\left(\frac{7}{3}\right)^{-1}\cdot\left(\frac{5}{3}\right)^6:\left(\frac{343}{625}\right)^{-2}\)
= ~ 0,0 145 . ~ 0,4 286 . ~ 21,4 335 / ~ 3,3 203
= ~ 0,0 062 . ~ 6,4 553
= ~ 0,04
c) 54 . 125 . ( 2,5 )-5 . 0,04
= 625 . 125 . 0,01 024 . 0,04
= 78 125 . 0,0 004 096
= 32
2 VIẾT DƯỚI DẠNG LUỸ THỪA CỦA 1 SỐ NGUYÊN:
a, 123: (3^4 .6^4)
b, 5^4 . 125 .(2.5)^-5 .0,04
c, (3/7)^5 .(7/3)^-1 -(5/3)^6 : (343/625)^-2
\(\left(\frac{3}{7}\right)^5.\left(\frac{7}{3}\right)^{-1}.\left(\frac{5}{3}\right)^6:\left(\frac{343}{625}\right)^{-2}\)
\(\left(\dfrac{3}{7}\right)^5.\left(\dfrac{7}{3}\right)^{-1}.\left(\dfrac{5}{3}\right)^6:\left(\dfrac{343}{625}\right)^{-2}\)
\(=\left(\dfrac{3}{7}\right)^5\cdot\left(\dfrac{3}{7}\right)\cdot\left(\dfrac{5}{3}\right)^6:\left(\dfrac{5^4}{7^3}\right)^2\)
\(=\dfrac{3^6}{7^6}\cdot\dfrac{5^6}{3^6}:\dfrac{5^8}{7^6}\)
\(=\dfrac{5^6}{5^8}=\dfrac{1}{25}\)
(3/7)5 x (7/3)-1 x (5/6)6 x (343/625)-2
viết biểu thức dưới dạng lũy thừa của 1 số nguyên
\(\left(\frac{3}{7}\right)^5.\left(\frac{7}{3}\right)^{-1}.\left(\frac{5}{6}\right)^6.\left(\frac{343}{625}\right)^{-2}\)
\(=\left(\frac{3}{7}\right)^5.\left(\frac{3}{7}\right).\left(\frac{5}{2.3}\right)^6.\left(\frac{5^4}{7^3}\right)^2\)
\(=\frac{3^5}{7^5}.\frac{3}{7}.\frac{5^6}{2^6.3^6}.\frac{5^8}{7^6}=\frac{1}{2^6}.\frac{3^6}{3^6}.\frac{5^{14}}{1}.\frac{1}{7^{12}}=\frac{5^{14}}{2^6.7^{12}}\)
Nó đâu có phải là số nguyên đâu
3/7 x 5/6 +5/6 x3/7
= (3/7x5/6) + (5/6x3/7)
= 15/42 + 15/42 = 30/42 = 5/7
Tính hợp lí: \(\left(\dfrac{3}{7}\right)^5\times\left(\dfrac{7}{3}\right)^{-1}\times\left(\dfrac{5}{3}\right)^6\div\left(\dfrac{343}{625}\right)^{-2}\)
\(=\left(\dfrac{3}{7}\right)^5\cdot\left(\dfrac{3}{7}\right)\cdot\left(\dfrac{5}{3}\right)^6:\left(\dfrac{625}{343}\right)^2\)
\(=\left(\dfrac{3}{7}\cdot\dfrac{5}{3}\right)^6:\left(\dfrac{625}{343}\right)^2\)
\(=\dfrac{5^6}{7^6}:\dfrac{5^8}{7^6}=\dfrac{1}{25}\)
Viết các biểu thức sau dưới dạng lũy thừa của 1soos nguyên
(3/7).(7/3)-1 .(5/3)6: (343/625)-2
a) 54 x125 x (2,5)-5 x 0,04
b) (3/7)5 x (7/3)-1 x (5/3)6 : (343/625)-2