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pro3182001
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Bài 2: Tính
a. $\dfrac{5- \dfrac{5}{3}+ \dfrac{5}{9}- \dfrac{5}{27}}{8- \dfrac{8}{3}+ \dfrac{8}{9}- \dfrac{8}{27}}: \dfrac{15- \dfrac{15}{11}+ \dfrac{15}{127}}{16- \dfrac{16}{11}+ \dfrac{16}{121}}$
$\dfrac{5- \dfrac{5}{3}+ \dfrac{5}{9}- \dfrac{5}{27}}{8- \dfrac{8}{3}+ \dfrac{8}{9}- \dfrac{8}{27}}$=5.(1-1/3+1/9+1/27)/8.(1-1/3+1/9+1/27)=5/8
làm tương tự với bên còn lại ta đc
5/8:15/16=2/3
cho phát đúng nha![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
a. $\dfrac{5- \dfrac{5}{3}+ \dfrac{5}{9}- \dfrac{5}{27}}{8- \dfrac{8}{3}+ \dfrac{8}{9}- \dfrac{8}{27}}: \dfrac{15- \dfrac{15}{11}+ \dfrac{15}{127}}{16- \dfrac{16}{11}+ \dfrac{16}{121}}$
$\dfrac{5- \dfrac{5}{3}+ \dfrac{5}{9}- \dfrac{5}{27}}{8- \dfrac{8}{3}+ \dfrac{8}{9}- \dfrac{8}{27}}$=5.(1-1/3+1/9+1/27)/8.(1-1/3+1/9+1/27)=5/8
làm tương tự với bên còn lại ta đc
5/8:15/16=2/3
cho phát đúng nha