b,(723+277).2001-(456+544).1010-389-611

=1000.2001-1000.1010-(389+611)

=1000.2001-1000.1010-1000

=1000.(2001-1010-1)

=1000.990

=990000

a, 9².53+12.9²-81+36.9²

=9².(53+12+36)-81

=81.101-81

=8181-81

=8100

đáp án là:2004456

2005 x 456 + 2004 x 544 = 2004456

Kết quả là : 2004456

Ta có :

456x36+456x61+4 x456+456

=456x(36+61+4+456)

=456x...tự tính

=...tự tính

Umm mình tưởng là cái 456 đó tính là 1 thôi chứ nhỉ ban???

\(456\times36+456\times61+4\times456+456\)

\(=456\times\left(36+61+4+1\right)\)

\(=456\times102\)

\(=45612\)

Học tốt

2010 x 2010 - 2009 x 2011

= ( 2011 - 2010 ) x 2010 - 2009 x 2011

= 2011 x 2010 - 1 x 2010 - 2009 x 2011

= 2011 x ( 2010 - 2009 ) - 1 x 2010

= 2011 x 1 - 2010 

= 2011 - 2010 

= 1

( 456 x 11 + 912 ) x 37 : ( 13 x 74 )

= ( 456 x 11 + 456 x 2 ) x 37 : ( 13 x 74 )

= [ 456 x ( 11 + 2 ) ] x 37 : ( 13 x 74 )

= [ 456 x 13 ] x 37 : ( 13 x 74 )

= 13 x 456 x 37 : ( 13 x 37 x 2 )

= 13 x 37 x 2 x 228 : ( 13 x 37 x 2 )

= ( 13 x 37 x 2 ) x 228 : ( 13 x 37 x 2 )

= ( 13 x 37 x 2 ) : ( 13 x 37 x 2 ) x 228

= 1 x 228

= 228

(44 x 52 x 60) : (11 x13 x 15 )

= [ ( 4 x 11 ) x ( 4 x 13 ) x ( 4 x 15 ) ] : (11 x13 x 15 )

= [ 4 x 11 x 4 x 13 x 4 x 15 ] : (11 x13 x 15 )

= [ ( 4 x 4 x 4 ) x ( 11 x 13 x 15 ) ] : (11 x13 x 15 )

= 64 x (11 x13 x 15 ) : (11 x13 x 15 )

= 64 x 1

= 64

a) 2010 x 2010 - 2009 x 2011 

= 2010 x 2010 - [ 2009 x ( 2010 +1) ]

=2010 x 2010 - 2009 x 2010 - 2009 

=2010( 2010 - 2009 ) -2009 

= 2010 -2019

= 1

c) ( 44 x 52 x60 ) : (11x13x15)

\(\frac{44\cdot52\cdot60}{11\cdot13\cdot15}=\frac{4\cdot11\cdot4\cdot13\cdot4\cdot15}{11\cdot13\cdot15}=64\)

B) (456 x 11 +912) x 37 : ( 13 x 74 )

= \(\frac{\left(456\cdot11+912\right)\cdot37}{13\cdot74}=\frac{\left[456\left(11+2\right)\right]\cdot37}{13\cdot37}=\frac{456\cdot13}{13\cdot2}=\frac{456}{2}=228\)

Nhớ k mik nha bn

(544x6-272x2x6)x(544x6+276)

=(544x6-544x6)x(544x6+276)

=0x(544x6+276)=0

=0000000000

(544 x 6 - 272 x 12 ) x ( 544 x 6 +276 )
=( 3264 - 3264 )       x (544 x 6 +276)
=    0                       x ( 544x6 + 276)
= 0
kết quả bằng 0 bởi vì số nào nhân với 0 đều bằng 0 bạn nhớ k và kb với mk nhé rất hân hạnh

\(\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+....+\frac{2}{x\left(x+1\right)}=\frac{499}{999}\)

\(\Leftrightarrow\frac{2}{6}+\frac{2}{12}+\frac{2}{20}+....+\frac{2}{x\left(x+1\right)}=\frac{499}{999}\)

\(\Leftrightarrow\frac{2}{2.3}+\frac{2}{3.4}+\frac{2}{4.5}+....+\frac{2}{x\left(x+1\right)}=\frac{499}{999}\)

\(\Leftrightarrow2\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+....+\frac{1}{x}-\frac{1}{x+1}\right)=\frac{499}{999}\)

\(\Leftrightarrow\frac{1}{2}-\frac{1}{x+1}=\frac{499}{999}\div2\)

\(\Leftrightarrow\frac{1}{x+1}=\frac{1}{2}-\frac{499}{1998}\)

\(\Leftrightarrow\frac{1}{x+1}=\frac{250}{999}\)

\(\Leftrightarrow\left(x+1\right).250=999\Rightarrow x+1=\frac{999}{250}\Rightarrow x=\frac{999}{250}-1=\frac{749}{250}\)

Như kiểu đề sai hay sao ý 

Ta có: X x 456 + X x 544 + X = 12000

          X x ( 456 + 544 + 1) = 12000

          X x 1001 = 12000

          X = 12000/1001

\(X\cdot456+X\cdot544+X=12000\)

\(X\cdot\left(456+544+1\right)=12000\)

\(X\cdot1001=12000\)

\(X=\frac{12000}{1001}\)

\(X=11\frac{989}{1001}\)

\(\cdot\)\(Là\)x (nhân) nha

x . 456 + x . 544 + x = 12000

x . 456 + x . 544 + x . 1 = 12000

x (456 + 544 + 1) = 12000

x . 1001 = 12000

x = 12000 : 1001

x = 11.98801198801

#Học tốt!!!

~NTTH~

Ta có:

\(\frac{x+4}{2008}+1+\frac{x+3}{2009}+1=\frac{x+2}{2010}+1+\frac{x+1}{2011}+1\)

\(\frac{x+2012}{2008}+\frac{x+2012}{2009}=\frac{x+2012}{2010}+\frac{x+2012}{2011}\)

\(\left(x+2012\right)\left(\frac{1}{2008}+\frac{1}{2009}-\frac{1}{2010}-\frac{1}{2011}\right)=0\)

\(x=-2012\)

;Ko tồn tại nghiệm số thực OK