x = 3/4

\(x=\dfrac{5}{8}+\dfrac{1}{8}\)

\(x=\dfrac{6}{8}=\dfrac{3}{4}\)

x = 3/4

Đặt \(A=\frac{1.2+2.4+3.6+4.8+5.10}{4+6.8+9.12+12.16+15.20}\)

\(\Rightarrow A=\frac{1.\left(1+2\right)+2.\left(1+2\right)+3.\left(1+2\right)+4.\left(1+2\right)+5.\left(1+2\right)}{4+2.\left(3+4\right)+3.\left(3+4\right)+4.\left(3+4\right)+5.\left(3+4\right)}\)

\(\Rightarrow A=\frac{\left(1+2+3+4+5\right).\left(1+2\right)}{4+\left(2+3+4+5\right).\left(3+4\right)}\)

\(\Rightarrow A=\frac{\left(1+5\right).5:2.\left(1+2\right)}{4+\left(2+5\right).4:2.\left(3+4\right)}\)

\(\Rightarrow A=\frac{6.5:2.3}{4+7.4:2.7}=\frac{45}{4+98}=\frac{45}{102}=\frac{15}{34}\)

Vậy \(A=\frac{15}{34}\)

Chúc bn học tốt

(4⁵ x 10 x 5⁶ + 25⁵ x 2⁸):(2⁸ x 5⁴ + 5⁷ x 2⁵)=1000

Lưu ý : 

Nếu không đủ các bước trên thì sẽ không được tính là làm đúng !

* = nhân nhé

( ( x . 32 ) - 17 ) . 2 = 42

( ( x . 32 ) - 17 ) = 42 : 2

( ( x . 32 ) - 17 ) = 21

x . 32 = 21 + 17

x . 32 = 38

x = 38 : 32

x = 19/16

88 - 3 . ( 7 + x ) = 64

3 . ( 7 + x ) = 88 - 64 

3 . ( 7 + x ) = 24

7 + x = 24 : 3 

7 + x = 8

x = 8 - 7

x = 1

6/7 * 5/8*7/3*7/6*8/5

= 6*5*7*7*8 /7*8*3*6*5

=1*1*7*1*1/1*1*3*1*1

= 7/3 

24877,731 đấy

a, 2x3x4x8x25x125= (2x3)x(4x25)x(8x125)= 6x100x1000=600000

b,42/5 +56/9+23/4+3/5+1/3+1/4= (42/5+3/5)+(23/4+1/4)+(56/9+1/3)=9+6+59/9=

a)  2 x 3 x 4 x 8 x 25 x 125=600000

b) 4 2/5 + 5 6/9 + 2 3/4 + 3/5 + 1/3 + 1/4=14

a)  2 x 3 x 4 x 8 x 25 x 125

=(2x3)x(4x25)x(8x125)

=6x100x1000

=600000

b) 4 2/5 + 5 6/9 + 2 3/4 + 3/5 + 1/3 + 1/4

(4+\(\frac{2}{5}\)+\(\frac{3}{5}\))+(5+\(\frac{6}{9}\)+1/3)+(2+\(\frac{3}{4}\)+\(\frac{1}{4}\))

=(4+1)+(5+1)+(2+1)

=5+6+3

=14