\(27+\left(43+11\right)-43-\left(27+11\right)\)

\(=27+43+11-43-27-11\)

\(=\left(27-27\right)+\left(43-43\right)+\left(11-11\right)\)

\(=0+0+0\)

\(=0\)

27+(43+11)-43-(27+11)

= 27 + 43 + 11 - 43 - 27 -11

= ( 27 - 27 ) + ( 43 - 43 ) + ( 11-11 )

= 0 + 0 + 0

=0

a. $\dfrac{14}{15}+\dfrac{2}{11}+\dfrac{1}{15}+\dfrac{4}{11}+\dfrac{10}{22}$

$=(\dfrac{14}{15}+dfrac{1}{15})+(\dfrac{2}{11}+\dfrac{4}{11}+\dfrac{10}{22})$

$=1+1=2$

b. $74\times43-43+27\times43$

$=(74-1+27)\times43$

$=100\times43=4300$

\(a)\dfrac{14}{15}+\dfrac{2}{11}+\dfrac{1}{15}+\dfrac{4}{11}+\dfrac{10}{22}\)

\(=\left(\dfrac{14}{15}+\dfrac{1}{15}\right)+\dfrac{2}{11}+\dfrac{4}{11}+\dfrac{5}{11}\)

\(=1+1=2\)

\(b)74\times43-43+27\times43\)

\(=43\times\left(74-1+27\right)\)

\(=43\times100=4300\)

a) \(\dfrac{14}{15}+\dfrac{2}{11}+\dfrac{1}{15}+\dfrac{4}{11}+\dfrac{10}{22}\)

= \(\left(\dfrac{14}{15}+\dfrac{1}{15}\right)+\left(\dfrac{2}{11}+\dfrac{4}{11}\right)+\dfrac{5}{11}\)

= \(1+\dfrac{6}{11}+\dfrac{5}{11}\)

= 2

b) 74 x 43 - 43 + 27 x 43

= 74 x 43 - 43 x 1 + 27 x 43

= 43 x ( 74 - 1 + 27 )

= 43 x 100

= 4300

43 × 11 = 473     86 × 11 = 946     73 × 11 = 803

\(\frac{5+8+11+14+...+68+71}{2\times43+3\times43+43\times5+7}\).

Xét tử số: 5+ 8+ 11+ 14+...+ 68.

Có số các số hạng là:

( 68- 5): 3+ 1= 22

Tử số là:

 ( 68+ 5)x 22: 2= 803

Xét mẫu số: 2x 43+ 3x 43+ 43x 5+ 7=( 2+ 3+ 5)x 43+ 7= 10x 43+ 7= 430+ 7= 437.

=> \(\frac{5+8+11+14+...+68+71}{2\times43+3\times43+43\times5+7}\)= \(\frac{803}{437}\).

[ 43 * 11 + 44 * 11 + 45 * 11 +46 *11 + 47 * 11 ] : [ 45 * 55 ]

= [ 11 x (43 + 44 + 45 + 46 + 47) ] : 2475
= 11 x 225 : 2475
= 2475 : 2475
= 1
1 đúng nhé! 100% là đúng 

bang1 tich cho minh nhe

=11*(43+44+45+46+47):(45*55)

=11*225:2475

=2475:2475

=1

D = 3\(\dfrac{1}{2}\) \(\times\) \(\dfrac{12}{43}\) + \(\dfrac{49}{14}\) \(\times\) \(\dfrac{31}{43}\) + \(\dfrac{11}{2}\)

D = \(\dfrac{7}{2}\) \(\times\) \(\dfrac{12}{43}\) + \(\dfrac{7}{2}\)  \(\times\) \(\dfrac{31}{43}\) + \(\dfrac{11}{2}\)

D = \(\dfrac{7}{2\times43}\) \(\times\) (12 + 31) + \(\dfrac{11}{2}\)

D = \(\dfrac{7}{2\times43}\)  \(\times\) 43 + \(\dfrac{11}{2}\)

D = \(\dfrac{7}{2}\) + \(\dfrac{11}{2}\)

D = 9

D = 3 và 1/2 x 12/43 + 49/14 x 31/43 + 11/2
= 7/2 x 12/43 + 49/14 x 31/43 + 11/2
= 42/43 +  217/36 + 11/2
=9

# https://lazi.vn/user/tnsociu

43^2004+43^2005=43^2004+43^2004.43

=43^2004.(1+43)

=43^2004.44

Ta có 43^2004  + 43^2005 = 43^2004 + 43^2004 x 43 

=43^2004 x (43 + 1) =43^2004 x 44

=43^2004 x 11 x 4 chia hết cho 11

\(-8x-\left(-11\right)=43\)

\(\Leftrightarrow-8x=43-11\)

\(\Leftrightarrow-8x=32\)

\(\Leftrightarrow x=\dfrac{32}{-8}\)

\(\Leftrightarrow x=-4\)

-8.x-(-11)=43

-8.x        =43+(-11)

-8.x        =32

    x        =32:(-8)

   x         =-4