Đáp án:
`E=-1/3`
`b) 1/100`
Giải thích các bước giải:
`E=(4^5.(9^4)-2.6^9)/(2^10.(3^8)+6^8.(20))`
`E=((2^2)^5.(3^2)^4-2.(2.3)^9)/(2^10.(3^8)+(2.3)^8.((2^2).5))`
`E=(2^10.(3^8)-2^10.(3^9))/(2^10.(3^8)+2^10.(3^8).5)`
`E=(2^10.(3^8).(1-3))/(2^10.(3^8).(1+5))`
`E=-2/6=-1/3`
`b) (5^4.(20^4))/(25^5.(4^5))`
`=(5^4.((2^2).5)^4)/((5^2)^5.(2^2)^5)`
`=(5^8.(2^8))/(5^10.(2^10))`
`=1/(5^2.(2^2))=1/(25.4)=1/100`