4 x 113 x 25 - 5 x 112 x 20

= 100 x 113 - 100 x 112

= 100 x (113 - 112)

= 100 x 1

= 100

4 x 113 x 25 - 5 x 112 x 20 = ( 4 x 25 ) x 113 - ( 5 x 20 ) x 112

                                        = 100 x 113 - 100 x 112

                                         = 11 300 - 11 200

                                         = 100.

4 x 113 x 25 - 5 x 112 x 20

= (4 x 25) x 113 - (5 x 20) x 112

= 100 x 113 - 100 x 112

= 100 x (113 - 112)

= 100 x 1

= 100

326 x 78 + 327 x 22

= 326 x 78 + (326 + 1) x 22

= 326 x 78 + 326 x 22 + 1 x 22

= 326 x (78 + 22) + 22

= 326 x 100 + 22

= 32600 + 22

= 32622

326 x 78 + 327 x 22

= 326 x 78 + (326 + 1) x 22

= 326 x 78 + 326 x 22 + 1 x 22

= 326 x (78 + 22) + 22

= 326 x 100 + 22

= 32600 + 22

= 32622

Tính  nhanh : 

326 x 78 + 327 x 22

= 326 x 78 + (326 + 1) x 22

= 326 x 78 + 326 x 22 + 1 x 22

= 326 x (78 + 22) + 22

= 326 x 100 + 22

= 32600 + 22

= 32622

\(\frac{\left(120+60\right)}{12}=\frac{120}{12}+\frac{60}{12}=10+5=15\)

\(78\cdot31+78\cdot17+78\cdot24+22\cdot72=78\left(31+17+24\right)+22\cdot72\)

\(=78\cdot72+22\cdot72=72\left(78+22\right)=72\cdot100=7200\)

\(997+86=997+\left(83+3\right)=\left(997+3\right)+83\)

\(=1000+83=1083\)

\(5\cdot25\cdot2\cdot37\cdot4=\left(5\cdot2\right)\cdot\left(25\cdot4\right)\cdot37\)

\(=10\cdot100\cdot37=37000\)

\(558+336+442+664=\left(558+442\right)+\left(336+664\right)\)

\(=1000+1000=2000\)

5 x 25 x 2 x 37 x 4

= ( 5 x 2 ) x ( 25 x 4 ) x 37

= 10 x 100 x 37

= 1000 x 37

= 37000

4 x 113 x 25 - 5 x 112 x 20

= 4 x 25 x 113 - 5 x 20 x 112

= 100 x 113 - 100 x 112

= 100 x (113 - 112)

= 100 x 1

= 100

   4 x 113 x 25 - 5 x 112 x 20 

= 4 x 25 x 113 - 5 x 20 x 112

= 100 x 113 - 100 x 112

= 100 x (113 - 112)

= 100 x 1 

= 100

Cách 1: 4 x 113 x 25 - 5 x 112 x 20

= (25 x 4) x 113 - (5 x 20) x 112

= 100 x 113 - 100 x 112

= 11300 - 11200

= 100

Cách 2: 4 x 113 x 25 - 5 x 112 x 20

= (25 x 4) x 113 - (5 x 20) x 112

= 100 x (113 - 112)

= 100 x 1

= 100

a) 75 x 48 - 9 x 90 + 6999

= 3600 - 810 + 6999

= 9789

~HT~

Bài này định tính nhanh kiểu gì?

\(a.13.\left(78+22\right)=13.100=1300\)

\(b.25.70+28.25+25.2=25.\left(70+28+2\right)=25.100=2500\)

\(c.\dfrac{15.3.14.2.19}{19.14.15}=6\)

\(d.\dfrac{132.70.60}{12.35.20}=\dfrac{11.12.35.2.20.3}{12.35.20}=66\)

c ) 815 - 23 - 77 + 185 

= ( 815 + 185 ) - ( 23 + 77 )

= 1000 - 100 = 900

m ) 8 x 427 x 3 + 6 x 573 x 4

= 24 x 427 + 24 x 573

= 24 x ( 427 + 573 ) 

= 24 x 1000

= 24000

g ) 52 - 42 + 37 + 28 - 38 + 63

= ( 52 + 28 ) - ( 42 + 38 ) + ( 37 + 63 )

= 80 - 80 + 100

= 0 + 100

= 100

h ) 35 x 18 - 9 x 70 + 100

= 7 x 5 x 9 x 2 - 9 x 7 x 5 x 2 + 100

= 0 + 100

= 100

n ) 2008 x 867 + 2009 x 133

= 2008 x 867 + ( 2008 + 1 ) x 133

= 2008 x 867 + 2008 x 133 + 133

= 2008 x ( 867 + 133 ) + 133

= 2008 x 1000 + 133

= 2008000 + 133

= 2008133

i ) 326 x 78 + 327 x 22

= 326 x 78 + ( 326 + 1 ) x 22

= 326 x 78 + 326 x 22 + 22

= 326 x ( 78 + 22 )  + 22

= 326 x 100 + 22

= 32600 +22

= 32622

q ) ( 20 + 21 + 22 + 23 + 24 + 25 ) x ( 16 - 2 x 8 ) 

= ( 20 + 21 + 22 + 23 + 24 + 25 ) x ( 16 - 16) 

= ( 20 + 21 + 22 + 23 + 24 + 25 ) x 0

= 0

thank bạn

\(25.5.4.125.20.8\)

\(=\left(25.4\right).\left(5.20\right).\left(125.8\right)\)

\(=100.100.1000\)

\(=10000000\)

25*(5+5)*4*20*8

=250*20+4+8

= 5000*12

=60000

đúng mk tích cho .

bằng 100

=11300-11200=100 

chúc bạn học tốt

BANG 100

CHUC BAN MAY MAN