a: =5*1,4-4*1,5+3*1,3

=7-6+3,9=4,9

b: =1/3*7+3/4*18-2/3*20

=7/3+54/4-40/3

=-11+54/4

=2,5

c: =5/6*17-1/2*16+2/5*15

=85/6-8+6

=85/6-2

=73/6

d: =15*4/5+12*3/4-18*4/9

=12+9-8

=12+1=13

a: \(3^7\cdot27^5\cdot81^3=3^7\cdot3^{15}\cdot3^{12}=3^{34}\)

b: \(36^5:18^5=\left(\dfrac{36}{18}\right)^5=2^5=32\)

c: \(24\cdot5^2+5^2\cdot5^3=24\cdot25+25\cdot125=25\cdot149=3725\)

d: \(\dfrac{125^4}{5^8}=\dfrac{5^{12}}{5^8}=5^4=625\)

a) \(3^7.27^5.81^3\)

\(=3^7.\left(3^3\right)^5.\left(3^4\right)^3\)

\(=3^7.3^{15}.3^{12}\)

\(=3^{34}\)

b) \(36^5:18^5\)

\(=\left(\dfrac{36}{18}\right)^5\)

\(=2^5\)

c) \(24.5^5+5^2.5^3\)

\(=24.5^5+5^5\)

\(=5^5.\left(24+1\right)\)

\(=5^5.25\)

\(=5^5.5^2=5^7\)

d) \(125^4:5^8\)

\(=\left(5^3\right)^4:5^8\)

\(=5^{12}:5^8\)

\(=5^4\)

a) 3⁷.27.81=3⁷.3¹⁵.3¹²=3^7+15+12=3³⁴

b)36:18

c)24.5+5.5

=5⁵.25

=5⁵.5²

=5⁷

d)125:5⁸=5¹²:5⁸=5⁴

ban tu lam di,luoi the

bai ki vay ,

a ) 9 < 3ⁿ : 3 < 81

= 3² < 3ⁿ : 3¹ < 3⁴ ;

= 3² < 3^n-1 < 3⁴ ; mà : 3² < 3³ < 3⁴

=> n  - 1 = 3

n = 3 + 1

n = 4

a)=180:90

=2

b)=240:24

=10

c)=6480:540

=12

d)171:9

=19

a, 180 : (18.5) = 180 :90 = 2

b, 240 : (2.3.4) = 240 : 24 = 10

c, (15.18.24)  : ( 5.9.12)

 = 6480 : 540 =12

d, ( 27 + 45 + 18 + 81) : 9

 = 3 + 5 + 2 + 9 = 19

a, 180 : (18 .5) = 180 : 90 = 2

b,  240 : ( 2.3.4) = 240 : 24= 10

c, ( 15. 18. 24 ) : ( 5.9.12) =6480 : 540=12

d, ( 27 +45 + 18 +81) : 9

  =  171 : 9

  = 19

Em nến gõ bằng công thức toán học em nhé. Như vậy mọi người nới hiểu đúng đề bài để trợ giúp cho em một cách tốt nhất em ạ!

a: \(\left(\dfrac{3}{4}-81\right)\left(\dfrac{3^2}{5}-81\right)\cdot...\cdot\left(\dfrac{3^{2000}}{2003}-81\right)\)

\(=\left(\dfrac{3^6}{9}-81\right)\left(\dfrac{3}{4}-81\right)\cdot\left(\dfrac{3^2}{5}-81\right)\cdot...\cdot\left(\dfrac{3^{2000}}{2003}-81\right)\)

\(=\left(81-81\right)\left(\dfrac{3}{4}-81\right)\cdot\left(\dfrac{3^2}{5}-81\right)\cdot...\cdot\left(\dfrac{3^{2000}}{2003}-81\right)\)

=0

b: \(\dfrac{69}{157}-\left(2+\left(3+4+5^{-1}\right)^{-1}\right)^{-1}\)

\(=\dfrac{69}{157}-\left(2+\left(3+4+\dfrac{1}{5}\right)^{-1}\right)^{-1}\)

\(=\dfrac{69}{157}-\left(2+1:\dfrac{36}{5}\right)^{-1}\)

\(=\dfrac{69}{157}-\left(2+\dfrac{5}{36}\right)^{-1}\)

\(=\dfrac{69}{157}-\left(\dfrac{77}{36}\right)^{-1}\)

\(=\dfrac{69}{157}-\dfrac{36}{77}=\dfrac{-339}{12089}\)

1).( 27,56 x 35 ) + ( 27,56 x 67 ) - ( 27,56 x 2)

= (964 + 1846,52) - 55,12

=2810,52 - 55,12

= 2755,4

2).( 4x 35 ) x ( 25 x 5 ) x 2

= ( 140 x 125 ) x2

= 17500 x 2

=35000

4). 3/10

5). 1188

6).  61/6

1)2756   2)35000   3)0   4)3/10   5)10/1/6

1,2755,4

2,35000

3,0

4,\(\frac{3}{10}\)

5,1188

6,\(\frac{61}{6}\)