=(1,8+1,2)+(0,66+0,34)=3+1=4

=6,48 x (1125-112 -13)=6,48 x 1000= 6480

=4,8 x ( 24,5 +15,6)=4,8 x 40,1 =192,48

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

a)  4,5 x 5,5 + 4,7 x 4,5

=4,5 x (5,5 +4,7)

=4,5 x 10,2

= 45,9

b) 7,5 x 2,5 x 0,04

=7,5 x (2,5 x 0,04)

=7,5 x 0,1

=0,75

c) 73,5 x 35, 64 ÷ 73,5 x 64,36

=73,5 x(35,64+64,36)

= 73,5 x 100

= 7350

d) 3,12 x 8 x 1,25

=3,12 x (8 x 1,25)

=3,12  x 10

= 31,2

e)6,48 x 11, 25 - 6,48 x 1,25

=6,48 x (11,25 -1,25)

= 6,48x 10

=64,8

f)3,67 x  58,35 + 58,35 x 6,33

=58,35 x (3,67+6,33)

= 58,35x 10

=583,5

You're welcome :))

A) \(4,5\times5,5+4,7\times4,5\)

\(=4,5\times\left(5,5+4,7\right)\)

\(=4,5\times10,2\)

\(=45,9\)

B) \(7,5\times2,5\times0,04\)

\(=7,5\times\left(2,5\times0,04\right)\)

\(=7,5\times0,1\)

\(=0,75\)

C) \(73,5\times35,64+73,5\times64,36\)

\(=73,5\times\left(35,64+64,36\right)\)

\(=73,5\times100\)

\(=7350\)

D) \(3,12\times8\times1,25\)

\(=3,12\times\left(8\times1,25\right)\)

\(=3,12\times10\)

\(=31,2\)

E) \(6,48\times11,25-6,48\times1,25\)

\(=6,48\times\left(11,25-1,25\right)\)

\(=6,48\times10\)

\(=64,8\)

F) \(3,67\times58,35+58,35\times6,33\)

\(=\left(3,67+6,33\right)\times58,35\)

\(=10\times58,35\)

\(=583,5\)

* Lần sau bạn tách câu hỏi ra để dễ giải hơn nhé *

​Hc tốt

@Duongg

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

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

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

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

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

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

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

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

= \(\dfrac{9}{11}\)

a;   123,6 : 125 : 8

   = 123,6 : (125 x 8)

= 123,6 : 1000

= 0,1236

b; 78,5 x 99 + 78,5

= 78,5 x 99 + 78,5 x 1

= 78,5 x (99 + 1)

= 78,5 x 100

= 7850

c; 6,48 x 1125 - 6,48  x 112   - 6,48 x 13

= 6,48 x (1125 - 112 - 13)

= 6,48 x 1000

= 6480

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

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

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

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

a: \(16.42\cdot0.05=0.821\)

b: \(49.36\cdot0.025=1.234\)

c: \(63.15\cdot0.02=1.263\)

bạn giải đúng rồi nhưng mà tách ra rồi làm nhé