a: =100x26=2600

b: =78x10=780

c: =67x100=6700

d: =1000x575=575000

\(4\times26\times25=\left(4\times25\right)\times26=100\times26=2600\\ 63\times78-53\times78=\left(63-53\right)\times78=10\times78=780\\ 67\times92+67\times8=67\times\left(92+8\right)=67\times100=6700\\ 8\times23\times25\times125=\left(8\times125\right)\times\left(23\times25\right)=1000\times575=57500\)

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

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

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

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

\(=1000+83=1083\)

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

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

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

\(=1000+1000=2000\)

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

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

Vậy giá trị cầ tìm là: 32622

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

Vậy giá trị cần tìmlaf 100

hok tốt

32622 và 100

a) 2 x 12 x 43 + 3 x 32 x 8 + 25 x 6 x4

=(2 x12) x43+(3 x8) x32+(6 x4) x25

=24 x43+24 x32+ 24 x25

=24 x(43+32+25)

=24 x100

=2400

b) 78 x 31 + 78 x 24 + 17 x 78 + 28 x 78

=78x(31+24+17+28)

=78x100

=7800

thanks bạn nha

378 x 46 + 189 x 72 - 4 x 78 x 25

= 17388 + 13608 - ( 4 x 25 ) x 78

= 17388 + 13608 - ( 100 x 78 )

= 17388 + 13608 - 7800

= ( 17388 - 7800 ) + 13608

= 9588 + 13608

= 23196

378 x 46 + 189 x 72 - 4 x 78 x 25 = 17388 + 13608 - ( 4 x 25 ) x 78

                                                      = 17388 + 13608 - ( 100 x 78 )

                                                      = 17388 + 13608 - 7800

                                                      = ( 17388 - 7800 ) + 13608

                                                      = 9588 + 13608

                                                      = 23196

Đáp án D

x + 1 4 - 1 3 : 2 + 1 6 - 1 4 = 7 46 = x + 1 4 - 1 3 : 23 12 = 7 46 x + 1 4 - 1 3 = 7 46 . 12 23 x + 1 4 - 1 3 = 7 24 x = 7 24 - 1 4 + 1 3 x = 3 8

Đáp án D

x + 1 4 - 1 3 : 2 + 1 6 - 1 4 = 7 46 = x + 1 4 - 1 3 : 23 12 = 7 46 x + 1 4 - 1 3 = 7 46 . 12 23 x + 1 4 - 1 3 = 7 24 x = 7 24 - 1 4 + 1 3 x = 3 8