2/3 x 4/5 + 4/5 x 8/3 = 4/5 x (2/3 + 8/3) = 4/5 x 10/3 = 8/3

27/32 x 16/9 -27/32 x7/9 + 27/32 

= 27/32 x (16/9 - 7/9 + 1 )

=27/32 x 2 

=27/16

\(\frac{2}{3}\) x   \(\frac{4}{5}\) +    \(\frac{4}{5}\) x     \(\frac{8}{3}\)

=\(\frac{4}{5}\) x    ( \(\frac{2}{3}\) +    \(\frac{8}{3}\) )

= \(\frac{4}{5}\) x    \(\frac{10}{3}\)

= \(\frac{40}{15}\) = \(\frac{8}{5}\)

\(32\times27+47\times73+27\times15\)

\(=\left(32\times27+27\times15\right)+47\times73\)

\(=27\times\left(32+15\right)+47\times73\)

\(=27\times47+47\times73\)

\(=47\times\left(27+73\right)\)

\(=47\times100\)

\(=4700\)

Học tốt

\(=32\cdot27+27\cdot15+47\cdot73\)  

\(=27\cdot\left(32+15\right)+47\cdot73\)   

\(=27\cdot47+47\cdot73\)   

\(=47\cdot\left(27+73\right)\)  

\(=47\cdot100\)   

\(=4700\)

32x27+47x73+27x15

=27x (32+15)+47x73

=27x47+47x73

=47x(27+73)

=47x100=4700

1. a. (x-45).27=0

=> x-45=0

=> x=0+45

=> x=45

b. 23.(42-x)=23

=> 42-x=23:23

=> 42-x=1

=> x=42-1

=> x=41

2. A=26+27+28+29+30+31+32+33

= (26+33)+(27+32)+(28+31)+(29+30)

= 59+59+59+59

= 59 . 4

= 236

3. 997+37=997+3+34=1000+34=1034

49+149=49+1+148=50+148=198

bài 1 

16*25*5*125*2*12

=16*125*125*24

=16*(125*125)*24

=16*15625*24

=6000000

bài 2 

a) x+37=121

    x        =121-37

    x        =84

b) 31+x+29=189

     31+x     =189-29

     31+x      = 160

c)129+x=170

           x =170-129

           x= 41

d) x-32*27=0

     x-32     =0:27

     x-32      =0

     x            =0+32

     x            =32

e)(x-3)*14=28

    x-3        =28:14

     x-3        =2

     x            =2+3

     x             =5

f) 15*x+2=45

    15*x    =45-2

    15*x     =43

         x      =43:15

         x       =\(\frac{43}{15}\)

g) (39-x)*32=32

    39-x        =32:32

     39-x        =1

          x         =39-1

         x           =38

h) (x-27)-145=0

     x-27         =0+145

     x-27         =145

     x              =145+27

     x                =172

chúc bạn học tốt

=3071

= 37x38+ (37x2)x27 - (37x3)x3

=37x38+37x (2 x 27) - 37 x (3x3)

= 37 x 38 + 37 x 54 - 37x 9

= 37x ( 38+54-9) 

= 37 x 83

= 3071

\(32.27+32.53\)

\(=32\left(27+53\right)\)

\(=32.80\)

\(=2560\)

32 x 27 + 32 x 53

= 32 x ( 27 + 53)

= 32 x 80

=2560

32 * 27 + 32 * 53 = 32 * ( 27 + 53 )

= 32 *  80

= 2560

a) \(\frac{27.45+55.27}{2+4+6+8+...+16+18}=\frac{27.\left(45+55\right)}{\left(2+18\right)+\left(16+4\right)+\left(14+6\right)+\left(12+8\right)}\)

\(=\frac{27.100}{20+20+20+20}=\frac{2700}{20.4}=\frac{2700}{80}=\frac{135}{4}\)

b) Lười

Làm giống câu a nhé

xin lỗi! mik ko rảnh

a ) 37 x 27 + 63 x 27 

= ( 37 + 63 ) x 27

= 100 x 27

= 2700

b ) 1 + 2 + 3 + 4 + ... + 97 + 98 + 99

= ( 99 - 1 ) : 1 + 1 

= 99 x ( 99 + 1 ) : 2 

= 4950

c ) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10

= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + ( 5 + 10 )

= 10 + 10 + 10 + 10 + 15

= 55

37 x 27 x 63 x27

=(37+63)x27

=100 x 27

37 x 27 + 63 x 27

= ( 37 + 63 ) x 27

= 100 x 27

= 2700

1 + 2 + 3 + 4 + ... + 97 + 98 + 99

= ( 1 + 99 ) + ( 2 + 98 ) + .... + ( 51 + 49 ) + 50

= 100 + 100 + ... + 100 + 50   ( có 49 số 100 )

= 100 x 49 + 50

= 4900 + 50

= 4950

1 + 2 + 3 +4 + 5 + 6 +7 + 8 + 9 + 10

= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + 10 + 5

= 10 + 10 + 10 + 10 +10 + 5

= 10 x 5 + 5

= 55