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Ba mũ mười sáu kia lớp hơn nhé 

10² = 10

10³ = 1 000

10⁴ = 10 000

10⁵ = 100 000

10⁶ = 1 000 000

10\(^2\)=100

10\(^3\)=1000

10\(^4\)=10000

10\(^5\)=100000

10\(^6\)=1000000

K nhé ????

10²=100

10³=1000

10⁴=10000

...

Câu 1:

1;   125 : 5²

   =   5³ : 5²

   =      5¹

2; 27⁵ : 81³

 = (3³)⁵ : (3⁴)³

 = 3¹⁵ : 3¹²

= 3³ 

3; 8⁴.16⁵.32

= (2³)⁴.(2⁴)⁵.2⁵

= 2¹².2²⁰.2⁵

= 2³⁷

Câu 1

4; 27⁴.81¹⁰

= (3³)⁴.(3⁴)¹⁰

= 3¹².3⁴⁰

= 3⁵²

Câu 2:

1; 125⁵ = (5³)⁵ = 5¹⁵

    25⁵ = (5²)⁵ = 5¹⁰ < 5¹⁵ < 125⁵

2; 3²⁰⁰ = (3²)¹⁰⁰ = 9¹⁰⁰

     2³⁰⁰ = (2³)¹⁰⁰ = 8¹⁰⁰ < 9¹⁰⁰ < 3²⁰⁰

Đặt A = 4 + 2² + 2³ + 2⁴ + ... + 2⁹ + 2¹⁰

          = 4 + ( 2² + 2³ + 2⁴ + ... + 2⁹ + 2¹⁰ )

Đặt B = 2² + 2³ + 2⁴ + ... + 2⁹ + 2¹⁰

=> 2B = 2( 2² + 2³ + 2⁴ + ... + 2⁹ + 2¹⁰ )

           = 2³ + 2⁴ + ... + 2¹⁰ + 2¹¹

=> B = 2B - B

         = 2³ + 2⁴ + ... + 2¹⁰ + 2¹¹ - ( 2² + 2³ + 2⁴ + ... + 2⁹ + 2¹⁰ )

         = 2³ + 2⁴ + ... + 2¹⁰ + 2¹¹ - 2² - 2³ - 2⁴ - ... - 2⁹ - 2¹⁰ 

         = 2¹¹ - 2² = 2¹¹ - 4

=> B = 2¹¹ - 4

Thế B vào A ta được :

A = 4 + 2¹¹ - 4 = 2¹¹

2 mũ 210

Ta có -15/x = 12/20 

suy ra 12.x = -15.20

           12.x = -300

            x = -300 : 12

            x = -25

a) \(12\cdot\left(-\dfrac{2}{3}\right)^2+\dfrac{4}{3}\)

\(=12\cdot\dfrac{4}{9}+\dfrac{4}{3}\)

\(=\dfrac{12\cdot4}{9}+\dfrac{4}{3}\)

\(=\dfrac{16}{3}+\dfrac{4}{3}\)

\(=\dfrac{16+4}{3}\)

\(=\dfrac{20}{3}\)

b) \(\left(\dfrac{3}{2}\right)^2-\left[0,5:2-\sqrt{81}\cdot\left(-\dfrac{1}{2}\right)^2\right]\)

\(=\dfrac{9}{4}-\left(\dfrac{1}{2}:2-9\cdot\dfrac{1}{4}\right)\)

\(=\dfrac{9}{4}-\left(\dfrac{1}{4}-9\cdot\dfrac{1}{4}\right)\)

\(=\dfrac{9}{4}-\dfrac{1}{4}\cdot\left(1-9\right)\)

\(=\dfrac{9}{4}+\dfrac{8}{4}\)

\(=\dfrac{17}{4}\) 

c) \(\left(-\dfrac{3}{4}+\dfrac{2}{3}\right):\dfrac{5}{11}+\left(-\dfrac{1}{4}+\dfrac{1}{3}\right)\)

\(=-\dfrac{1}{12}:\dfrac{5}{11}+\dfrac{1}{12}\)

\(=\dfrac{1}{12}\cdot-\dfrac{11}{5}+\dfrac{1}{12}\)

\(=\dfrac{1}{12}\cdot\left(-\dfrac{11}{5}+1\right)\)

\(=\dfrac{1}{12}\cdot-\dfrac{6}{5}\)

\(=-\dfrac{1}{10}\) 

d) \(\dfrac{\left(-1\right)^3}{15}+\left(-\dfrac{2}{3}\right)^2:2\dfrac{2}{3}-\left|-\dfrac{5}{6}\right|\)

\(=-\dfrac{1}{15}+\dfrac{4}{9}:\left(2+\dfrac{2}{3}\right)-\dfrac{5}{6}\)

\(=-\dfrac{1}{15}+\dfrac{4}{9}:\dfrac{8}{3}-\dfrac{5}{6}\)

\(=-\dfrac{9}{10}+\dfrac{1}{6}\)

\(=-\dfrac{11}{15}\) 

e) \(\dfrac{3^7\cdot8^6}{6^6\cdot\left(-2\right)^{12}}\)

\(=\dfrac{3^7\cdot\left(2^3\right)^6}{2^6\cdot3^6\cdot2^{12}}\)

\(=\dfrac{3^7\cdot2^{18}}{2^{6+12}\cdot3^6}\)

\(=\dfrac{2^{18}\cdot3^7}{2^{18}\cdot3^6}\)

\(=3^{7-6}\)

\(=3\)

\(a,12\cdot\left(-\dfrac{2}{3}\right)^2+\dfrac{4}{3}\\ =12\cdot\dfrac{4}{9}+\dfrac{4}{3}\\ =\dfrac{16}{3}+\dfrac{4}{3}\\ =\dfrac{20}{3}\\ b,\left(\dfrac{3}{2}\right)^2-\left[0,5:2-\sqrt{81}.\left(-\dfrac{1}{2}\right)^2\right]\\ =\dfrac{9}{4}-\left(\dfrac{1}{2}\cdot\dfrac{1}{2}-9\cdot\dfrac{1}{4}\right)\\ =\dfrac{9}{4}-\left(\dfrac{1}{4}-\dfrac{9}{4}\right)\\ =\dfrac{9}{4}-\left(-\dfrac{8}{4}\right)\\ =\dfrac{17}{4}\)

\(c,\left(-\dfrac{3}{4}+\dfrac{2}{3}\right):\dfrac{5}{11}+\left(-\dfrac{1}{4}+\dfrac{1}{3}\right)\\ =\left(-\dfrac{9}{12}+\dfrac{8}{12}\right)\cdot\dfrac{11}{5}+\left(-\dfrac{3}{12}+\dfrac{4}{12}\right)\\ =-\dfrac{1}{12}\cdot\dfrac{11}{5}+\dfrac{1}{12}\\ =-\dfrac{11}{60}+\dfrac{1}{12}\\ =-\dfrac{1}{10}\)

\(d,\dfrac{-1^3}{15}+\left(-\dfrac{2}{3}\right)^2:2\dfrac{2}{3}-\left(-\dfrac{5}{6}\right)\\ =-\dfrac{1}{15}+\dfrac{4}{9}\cdot\dfrac{3}{8}+\dfrac{5}{6}\\ =-\dfrac{1}{15}+\dfrac{1}{6}+\dfrac{5}{6}\\ =\dfrac{1}{10}+\dfrac{5}{6}\\ =\dfrac{14}{15}\)

`e,` Không hiểu đề á c: )

dễ, nhưng phai giai dc câu nay  60% nhan x cong 2 phan 3 = 1 phan 3 nhan 6va 1 phan 3

dễ mà

         Giải

Ta có : 5.A = 5 . ( 1 + 5 + 5² + .... + 5²⁰¹⁹ )

                  = 5 + 5² +5 ³ + ... + 5²⁰²⁰

Suy ra : 5A - A = ( 5 + 5² + 5³ + ... + 5²⁰¹⁹ + 5²⁰²⁰ ) - ( 1 + 5 + 5² + ... + 5²⁰¹⁹ )

              A = 5²⁰²⁰ - 1

Vậy A = 5²⁰²⁰ -1

# Chúc bạn học tốt #

5A = 1 + 5.( 5 + 5² + 5^x + .... + 5²⁰¹⁹ )

5A = 1 + 5² + 5^x +....+ 5²⁰²⁰

5A - A = 1 + ( 5² + 5^x +.....+ 5²⁰²⁰ ) - ( 5 + 5² + 5^x +.....+ 5²⁰¹⁹ )

4A = 1 + 5²⁰²⁰ - 5

A = 1 + ( 5²⁰²⁰ - 5 ) : 4

Sai thì thôi bn nhé !!!

A=1+5+5mũ 2 +......+5 mũ 2019

A*5=5*(1+5+5 mũ 2+....+5 mũ 2019)