=81*(27+9^15):(3^5+3^32)

\(=\dfrac{3^4\cdot\left(3^3+3^{30}\right)}{3^5+3^{32}}=\dfrac{3^7\left(1+3^{27}\right)}{3^5\left(1+3^{27}\right)}=\dfrac{3^7}{3^5}=9\)

=19701

81. (27 + 9¹⁵) : ( 3⁵ + 3³²)

= 81 . (3³ +(3²)¹⁵) :(3⁵ + 3³²)

= 3⁴ . (3³ + 3^2.15) :(3⁵ + 3³²)

= 3² .(3²​ . (3³ + 3³⁰) :(3⁵ + 3³²)

= 9 .(3² . 3³ + 3² . 3³⁰) : (3⁵ + 3³²)

= 9 . (3⁵ + 3³²) : (3⁵ + 3³²)

= 9 . 1

= 9

tại sao đg 3^4 lại chuyển thành 3^2 bn

a) 2^7 . 9^3 / 6^5 . 8^2

= 2^7 . 3^9 / 2^5 . 3^5 . 2^6

= 2^-4 . 3^4

`@` `\text {Ans}`

`\downarrow`

`a,`

`5.125.25 \div 5^6`

`=`\(5\cdot5^3\cdot5^2\div5^6\)

`=`\(5^{1+3+2-6}=5^{6-6}=5^0=1\) 

`b,`

\(2^{14}\div\left(2^6\cdot32\right)\)

`=`\(2^{14}\div\left(2^6\cdot2^5\right)\)

`=`\(2^{14}\div2^{11}=2^3\)

`c,`

`3.3^5\div 27`

`=`\(3\cdot3^5\div3^3\)

`=`\(3^{1+5-3}\)

`=`\(3^3\) 

`d,`

\(2^{15}\div\left(2^6\cdot32\right)=2^{15}\div\left(2^6\cdot2^5\right)=2^{15}\div2^{11}=2^4\)

`e,`

\(3^2\cdot27\div81=3^2\cdot3^3\div3^4=3\)

`g,`

\(100\cdot1000\cdot10000-10^9=10^2\cdot10^3\cdot10^4-10^9\)

`=`\(10^9-10^9=0\)

`h,`

\(125^4\div5^9=\left(5^3\right)^4\div5^9=5^{12}\div5^9=5^3\)

a) 1

b) 8

c) 27

d) 16

e) 3

g) 0

h) 125

câu cuối là 999,7650928....

rồi mà, câu 3 là 100 

khó quá tui chưa học