a: \(5\cdot11\cdot18+9\cdot31\cdot10+4\cdot29\cdot45\)

\(=11\cdot\left(5\cdot18\right)+31\cdot\left(9\cdot10\right)+29\cdot2\cdot\left(2\cdot45\right)\)

\(=90\left(11+31+29\cdot2\right)\)

\(=90\cdot100=9000\)

b: \(37\cdot39+78\cdot14+13\cdot85+52\cdot55\)

\(=37\cdot39+39\cdot2\cdot14+13\cdot85+13\cdot4\cdot55\)

\(=39\left(37+2\cdot14\right)+13\cdot\left(85+4\cdot55\right)\)

\(=39\cdot65+13\cdot305\)

\(=13\left(65\cdot3+305\right)=13\cdot500=6500\)

a)

5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45

=90.11+90.31+2.29.90=90.11+90.31+2.29.90

=90.(11+31+2.29)=90.(11+31+2.29)

=90.100=9000

b)

37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55

=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11

=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44

=39.65+65.(17+44)=39.65+65.(17+44)

=39.65+65.61=39.65+65.61

=65.(39+61)=65.(39+61)

=65.100=6500

Ko ghi lại đề!!

= (-8)[(-37-17)+35]-11 = (-8)(-54+35)-11

= (-8)(-19)-11 = 152-11 = 141

*Tính hợp lí nhưng thấy chưa hợp lí cho lắm hehe!!*

256 x 786 x 2321 x 213

\(a,\left(-37-17\right).\left(-9\right)+35.\left(-9-11\right)\)

\(=\left(-54\right).\left(-9\right)+35.\left(-20\right)\)

\(=486+\left(-700\right)\)

\(=-214\)

\(b,\left(-25\right).\left(75-25\right)-75.\left(45-25\right)\)

\(=\left(-25\right).50-75.20\)

\(=\left(-25\right).50+\left(-25\right).3.20\)

\(=\left(-25\right).50+\left(-25\right).60\)

\(=\left(-25\right).\left(50+60\right)\)

\(=\left(-25\right).110\)

\(=-2750\)

\(c,136.\left(-47\right)+36.47\)

\(=47.\left(-136+36\right)\)

\(=47.\left(-100\right)\)

\(=-4700\)

a)

5.11.18+9.31.10+4.29.455.11.18+9.31.10+4.29.45

=90.11+90.31+2.29.90=90.11+90.31+2.29.90

=90.(11+31+2.29)=90.(11+31+2.29)

=90.100=9000

b)

37.39+78.14+13.85+52.5537.39+78.14+13.85+52.55

=37.39+39.2.14+13.5.17+13.4.5.11=37.39+39.2.14+13.5.17+13.4.5.11

=39.(37+2.14)+65.17+65.44=39.(37+2.14)+65.17+65.44

=39.65+65.(17+44)=39.65+65.(17+44)

=39.65+65.61=39.65+65.61

=65.(39+61)=65.(39+61)

=65.100=6500

a.(5.18).11+(9.10).31+2.2.29.45

=90.11+90.31+(2.45).2.29

=90.11+90.31+90.2.29

=90.(11+31+2.29)

=90.100

=9000

Câu a:

Ta thấy 37 - 37 = 0

nên nhóm lại kết quả là 14 + 26 = 40

Câu b:

tương tự, kết quả là 6 + 10 = 16

Các câu còn lại như vậy

( -37)+14 +26 +37

=( -37 )+ 37 + (14 + 26 )

=0 +40 = 40 

- 24 + 6  +10 +24 

=( -24 ) + 24 +(  6 + 10 ) 

=0 + 16 = 16

15 + 23 + (-25 ) + ( -23 )

= 15 + ( -25 ) + 23 +( -23 )

= -10 + 0 

= - 10

là sao hả bạn

bai này mình cần sự giúp đỡ của các bạn

1) 125.(-24) + 24.225.

\(=24\left(-125+225\right)=24.100=2400.\)

2) 512.(2 – 128) – 128. (-512).

\(=512\left(2-128+128\right)=512.2=1024.\)

câu 1 = -68

câu 2 =-2500

câu 3=168

câu 4 =4571

câu 6=124

( -37 ) + 14 + 26 + 37 = [ ( -37 ) + 37 ] + ( 14 + 26 ) = 0 + 40 = 40

1. ( -24 ) + 6 + 10 + 24 = [ ( -24 ) + 24 ] + ( 6 + 10 ) = 0 + 16 = 16

2. 15 + 23 + ( -25 ) + ( -23 ) = [ 15 + ( -25 ) ] + [ 23 + ( -23 ) = ( -10 ) + 0 = -10 

3. 60 + 33 + ( -50 ) + ( -33 ) = [ 60 + ( -50 ) ] + [ 33 + ( -33 ) ] = 10 + 0 = 10

4. ( -16 ) + ( -209 ) + ( -14 ) + 209 = [ ( -16 ) + ( -24 ) ] + [ ( -209 ) + 209 ] - ( -40 ) + 0 = -40

5.( -12 ) + ( -13 ) + 36 + ( -11 ) = [ ( -12 ) + ( -13 ) + ( -11 ) ] + 36 = ( -36 ) + 36 = 0

6. ( -16 ) + 24 + 16 - 34 = [ ( -16 ) + 16 ] + ( 24 - 34 ) = 0 + ( - 10 )  = -10

7. 25 + 37 - 48 - 25 - 37 = ( 25 - 25 ) + ( 37 - 37 ) - 48 = 0 + 0 - 48 = -48

8. 2575 + 37 - 2576 - 29 = ( 2575 - 2576 ) + ( 37 - 29 ) = ( -1 ) + 8 = 7

 34 + 35 + 36 - 14 - 15 - 16 - 17 = ( 34 - 14 ) + ( 35 - 15 ) + ( 36 - 16 ) - 17 = 20 + 20 + 20 - 17 = 60 - 17 = 43

OK

• (-37)+14+26+37 = (-37+37)+(14+26)

                            = 0+ ( 14+26)

                            = 0+ 40 = 40

*1.) (-24)+6+10+24 = (-24+24)+(6+10)

                          = 0+ 16 = 16

2.) 15+23+(-25)+(-23) = (23+-23)+(15+-25)

                               = 0 + -10 = -10

3.) 60+33+(-50)+(-33) = (33+-33)+(60+(-50)

                               = 0+ 10 = 10

4.) (-16)+(-209)+(-14)+209 = (-209+209)+(-16+-14)

                                      = 0+ -30 = -30

5.) (-12) +(-13)+36+(-11) = (-12+-13+-11)+36

                                   = -36 + 36 = 0

 6.) -16 +24 +16-34 = (-16+16)+(24-34)

                             = 0+ -10 = -10

8.) 2575 +37-2575-29 =(2575-2575)+(37 -29)

                               = 0 + 8 = 8

•  34 +35+36+37 -14-15-16-17

         = (34-14)+(35-15)+(36-16)+(37-17)

          = 10+10+10+10

          = 10 . 4 = 40