câu hỏi là j ạ

5⁶ : 5⁴ + 3 . 3² = 2021  câu hỏi của mik đây nhé bn

`5 xx 125 xx 4 xx 8 xx 25`

`= (125 xx 8) xx (4 xx 25) xx 5`

`= 1000 xx 100 xx 5`

`= 500000`

`5 xx 125 xx 4 xx  8 xx 25`

`=(125 xx 8) xx ( 4 xx 25) xx 5`

`= 1000 xx 100 xx 5`

`=100000 xx 5`

`=500000`

b 3 chữ số

tui nghĩ thế

b

`7 + 2(x-3)=11`

`2(x-3)=11-7`

`2(x-3)=4`

`x-3=4:2`

`x-3=2`

`x=2+3`

`x=5`

7 + 2 ( x - 3) = 11

 2 ( x -3) = 11 - 7

2 ( x - 3) = 4

   x - 3 = 4 : 2

 x - 3 = 2

x = 2 + 3

x = 5

ok có mặt

2.3^x = 10.3¹² + 8.27⁴

2.3^x = 10.3¹² + 8 . (3³)⁴

2.3^x = 10.3¹² + 8 . 3¹²

2.3^x = 3¹² . 18 

3^x = 3¹² . 9

3^x = 3¹² . 3²

3^x = 3¹⁴

x = 14 

(4x -1)³ = 27 . 125

(4x -1) ³ = 3³ . 5³

(4x-1)³ = 15³

^{4x - 1 = 15}

^{4x = 15 + 1}

^{4x = 16}

^{x = 16 : 4}

^{x = 4}

3/4+2/7+1/4-3/5+5/7

= 3/4+1/4+ 2/7+5/7-3/5

= 1 + 1 - 3/5

= 2 - 3/5

= 7/5

      \(\dfrac{3}{4}\) + \(\dfrac{2}{7}\) + \(\dfrac{1}{4}\) - \(\dfrac{3}{5}\) + \(\dfrac{5}{7}\)

= ( \(\dfrac{3}{4}\)+ \(\dfrac{1}{4}\) ) + ( \(\dfrac{2}{7}\) + \(\dfrac{5}{7}\)) - \(\dfrac{3}{5}\)

= 1 + 1 -  \(\dfrac{3}{5}\)

= 2 - \(\dfrac{3}{5}\)

= \(\dfrac{10}{5}\) - \(\dfrac{3}{5}\)

= \(\dfrac{7}{5}\)

   9 x 24 x 25 

= 9 x 6 x 4 x 25

= 54 x 100

= 5400

       12 x125 x54 

=   3 x 4 x 2 x 27 x 125

= 3 x 27 x 8 x 125

= 81 x 1000

= 81000

   425 x 7 x 4 - 170 x 60

=  425 x 4 x 7  - 1700 x 6

= 1700 x 7 - 1700 x 6

= 1700

2²²⁵ và 3¹⁵⁰

2²²⁵ =  (2³)⁷⁵  = 8⁷⁵

3¹⁵⁰ = (3²)⁷⁵ = 9⁷⁵

2²²⁵ = 8⁷⁵ < 9⁷⁵ = 3¹⁵⁰ 

vậy 2²²⁵ < 3¹⁵⁰