20,23 : 0,25 + 20,23 : 0,1 + 20,23 + 85 x 20,23

= 20,23 x 4 + 20,23 x 10 + 20,23 x 1 + 85 x 20,23

= 20,23 x (4 + 10 + 1 + 85)

= 20,23 x 100

= 2023

 20,23 : 0,25 + 20,23 : 0,1 + 20,23 + 85 x 20,23

= 20,23 x 4 + 20,23 x 10 + 20,23 + 85 x 20,23

= 20,23 x ( 4 + 10 + 1 + 85 )

= 20,23 x 100

= 2023

a: =20,23(15,75+85,25-1)

=20,23*100

=2023

b: =4+4=8

c: =6,48(111-1-10)=648

d: =1,25*8*0,25*4

=10

a. 20,23 x 15,75 + 20,23 x 85,25 - 20,23

 = 20,23 . (15,75 + 85,25 - 1)

= 20,23 . 100

= 2023

b.0,66 + 1,2+ 3,34+2,8 

= 4+4

= 8

c.111 x 6,48 -6,48 - 6,48 x 10

 = 6,48 . (111 - 1 -10)

= 648

d.1,25 x 0,25 x 8 x 4

 = 1,25 . 8 . 0,25 . 4

= 10

a: \(20,23\cdot7,5+20,23+20,23+20,23:2\)

\(=20,23\cdot7,5+20,23\cdot2+20,23\cdot0,5\)

\(=20,23\left(7,5+2+0,5\right)\)

\(=20,23\cdot10=202,3\)

b: \(100:9-79,3:9\)

\(=\left(100-79,3\right):9\)

\(=20,7:9=2,3\)

20,23*20,24-20,22*8,25-20,22*5,9-2,022*60,9

=20,23*20,24-20,22(8,25+5,9+6,09)

=20,23*20,24-20,22*20,24

=20,24*(-0,01)

=-0,2024

\(\text{25 x 20,23 + 105 x 20,23 - 20,25 x 20,23 - 9,75 x 20,23}\\ =20,23\text{ x }\left(25+105-9,75-20,25\right)\\ =20.23\text{ x }100=2023\)

\(\dfrac{5}{13}\times\dfrac{7}{11}+\dfrac{5}{13}\times\dfrac{2}{11}+\dfrac{8}{13}\times\dfrac{9}{11}\)

\(=\dfrac{5}{13}\times\left(\dfrac{7}{11}+\dfrac{2}{11}\right)+\dfrac{8}{13}\times\dfrac{9}{11}\)

\(=\dfrac{5}{13}\times\dfrac{9}{11}+\dfrac{8}{13}\times\dfrac{9}{11}\)

\(=\dfrac{9}{11}\times\left(\dfrac{5}{13}+\dfrac{8}{13}\right)\)

\(=\dfrac{9}{11}\times1\)

\(=\dfrac{9}{11}\)

a) \(20,23\times21+20,23\times80-20,23\)

\(=20,23\times\left(21+80-1\right)\)

\(=20,23\times100\)

\(=2023\)

\(\dfrac{5}{13}\) \(\times\) \(\dfrac{7}{11}\) + \(\dfrac{5}{13}\) \(\times\) \(\dfrac{2}{11}\) + \(\dfrac{8}{13}\) \(\times\) \(\dfrac{9}{11}\)

= \(\left(\dfrac{5}{13}\times\dfrac{7}{11}+\dfrac{5}{13}\times\dfrac{2}{11}\right)\)+ \(\dfrac{8}{13}\) \(\times\) \(\dfrac{9}{11}\)

= \(\dfrac{5}{13}\)\(\times\) (\(\dfrac{7}{11}\) + \(\dfrac{2}{11}\)) + \(\dfrac{8}{13}\) \(\times\) \(\dfrac{9}{11}\)

= \(\dfrac{5}{13}\) \(\times\) \(\dfrac{9}{11}\) + \(\dfrac{8}{13}\) \(\times\) \(\dfrac{9}{11}\)

= \(\dfrac{9}{11}\) \(\times\)( \(\dfrac{5}{13}\) +\(\dfrac{8}{13}\))

= \(\dfrac{9}{11}\) \(\times\) 1

= \(\dfrac{9}{11}\)

Lời giải:
$2,5\times 20,23\times 8\times 5=2,5\times 20,23\times 4\times 2\times 5$

$=(2,5\times 4)\times 20,23\times (2\times 5)$

$=10\times 20,23\times 10=20,23\times 100=2023$

a: =20,23(15,75+85,25-1)

=20,23*100

=2023

b: =0,66+3,34+2,8+1,2

=4+4

=8

20,23 x 15,75 + 20,23 x 85,25 - 20,23

=2023 x (15,75+85,25-1)

= 2023 x 100

=202300

0,66 + 1,2 + 3,34 + 2,8

=(0,66+3,34)+(1,2+2,8)

=4+4

=8

    20,23 \(\times\) 37 - 2,3 \(\times\) 5,5 + 20,23 \(\times\) 63 - 2,3 \(\times\) 4,5

= ( 20,23 \(\times\) 37 + 20,23 \(\times\) 63 ) - ( 2,3 \(\times\) 5,5 + 2,3 \(\times\) 4,5)

= 20,23 \(\times\) ( 37 + 63) - 2,3 \(\times\) ( 5,5 + 4,5)

= 20,23 \(\times\) 100 - 2,3 \(\times\) 10

= 2023 - 23

= 2000