\(\left(1+\frac{1}{2}\right)\left(1+\frac{1}{3}\right)..\left(1+\frac{1}{2019}\right)\)

\(=\frac{3}{2}\cdot\frac{4}{3}\cdot...\cdot\frac{2020}{2019}\)

\(=\frac{2020}{2}=1010\)

\(\left(1+\frac{1}{2}\right)\left(1+\frac{1}{3}\right)...\left(1+\frac{1}{2019}\right)\)

\(=\frac{3}{2}\cdot\frac{4}{3}\cdot...\cdot\frac{2020}{2019}\)

\(=\frac{2020}{2}\)

\(=1010\)

?????????????????

2/

y=o

5x-2x=6-7x

( 1.1 x 1.2 x 1.3 x 1.4 x 1.5 x 1.6 ) x ( 1.25 - 0.25 x 5 ) 

=( 1,1 x 1,2 x1,3 x1,4 x1,5 x1,6 ) x ( 1,25 - 1,25 )

=( 1.1x1,2 x1,3 x1,4 x1,5 x1,6 ) x 0

=0 

=39 

tính máy tính nha bạn chính xác 100 % 

a: =>78/4+x=30

=>x=30-78/4=42/4=10,5

b: =>x-2/3=1/6

=>x=1/6+2/3=5/6

c: =>16/3-x=7/4

=>x=16/3-7/4=43/12

\(\left(x+0.3\right)+\left(x+0.7\right)+......+\left(x+4.7\right)+\left(x+5.1\right)=48.1\)

\(x+0.3+x+0.7+......+x+4.7+x+5.1=48.1\)

\(\left(x+x+......+x\right)+\left(0.3+0.7+......+5.1\right)=48.1\)( 13 số x )

\(13x+35.1=48.1\)

\(13x=48.1-35.1=13\)

\(x=13:13=1\)

( x + 0.3 ) + ( x + 0.7 ) + ... + ( x + 5.1 ) = 48.1

( x + x + ... + x ) + ( 0.3 + 0.7 + .... + 5.1 ) = 48.1 ( có 13 số x )

13x + 35.1 = 48.1

13x = 13

x = 13 : 13 = 1

Ai đúng mình k cho

ta có :

(x+0.3) + (x+0.7) + (x+1.1) +...+ (x+4.7) + (x+5.1) =48.1

(x+x+x+...+x) + (0.3+0.7+1.1+...+5.1)=48.1

  13 số hạng x

13x + 35.1=48.1

13x=13

x=1