1: \(78+22+18\)

\(=\left(78+22\right)+18\)

=100+18

=118

2: \(94+563+\left(106-563\right)-\left(-70\right)\)

\(=94+563+106-563+70\)

\(=\left(94+106\right)-\left(563-563\right)+70\)

=100-0+70

=170

3: \(25\cdot154-25+47\cdot25\)

\(=25\left(154-1+47\right)\)

\(=25\cdot200=5000\)

4: \(\left[5^{29}+5^{30}\left(16-11\right)\right]:5^{29}\)

\(=\left(5^{29}+5^{30}\cdot5\right):5^{29}\)

\(=\dfrac{5^{29}\cdot1+5^{29}\cdot5^2}{5^{29}}\)

\(=1+5^2=26\)

8: \(25\cdot2^3-\left(9-14\right)+\left(29-34+20\right)\)

\(=25\cdot8-\left(-5\right)+\left(-5\right)+20\)

\(=200+5-5+20\)

=220

1) $(-81)\cdot27-3^4\cdot(-77)$

$=(-81)\cdot27-81\cdot(-77)$

$=-81\cdot[27+(-77)]$

$=-81\cdot(27-77)$

$=-81\cdot(-50)$

$=81\cdot50$

$=4050$

2) $(-16)\cdot32-(-4)^2\cdot18$

$=(-16)\cdot32-16\cdot18$

$=-16\cdot(32+18)$

$=-16\cdot50$

$=-800$

3) $(-2)^4\cdot289-16\cdot189$

$=16\cdot289+16\cdot(-189)$

$=16\cdot[289+(-189)]$

$=16\cdot(289-189)$

$=16\cdot100$

$=1600$

4) $41\cdot(-18)+41\cdot(-81)-41$

$=1\cdot(-18)+41\cdot(-81)+41\cdot(-1)$

$=41\cdot[(-18)+(-81)+(-1)]$

$=41\cdot(-18-81-1)$

$=41\cdot(-99-1)$

$=41\cdot(-100)$

$=-4100$

5) $17\cdot(-37)-23\cdot37-46\cdot(-37)$

$=17\cdot(-37)+23\cdot(-37)-46\cdot(-37)$

$=-37\cdot(17+23-46)$

$=-37\cdot(40-46)$

$=-37\cdot(-6)$

$=37\cdot6$

$=222$

6) $-48+48\cdot(-78)+48\cdot(-21)$

$=48\cdot(-1)+48\cdot(-78)+48\cdot(-21)$

$=48\cdot[(-1)+(-78)+(-21)]$

$=48\cdot(-1-78-21)$

$=48\cdot(-79-21)$

$=48\cdot(-100)$

$=-4800$

7) $29\cdot(-13)+27\cdot(-29)+(-14)\cdot(-29)$

$=-29\cdot13+27\cdot(-29)+(-14)\cdot(-29)$

$=-29\cdot[13+27+(-14)]$

$=-29\cdot(40-14)$

$=-29\cdot26$

$=-754$

$\text{#}Toru$

\(\text{( -12 ) + ( -13 ) + 36 + ( - 11 )}\)

\(=\left[\left(-12\right)+\left(-13\right)+\left(-11\right)\right]+36\)

\(=\left(-36\right)+36\)

\(=0\)

\(\text{- 16 + 24 + 16 _ 34}\)

\(=\left(-16+16\right)+\left(24-34\right)\)

\(=0+\left(-10\right)\)

\(=-10\)

\(\text{25 + 37 _ 48 _ 25_ 37}\)

\(=\left(25-25\right)+\left(37-37\right)-48\)

\(=0+0-48\)

\(=-48\)

\(\text{2575 + 37 _ 2576 _ 29}\)

\(=\left(2575-2576\right)+\left(37-29\right)\)

\(=\left(-1\right)+8\)

\(=7\)

\(\text{34 + 35 + 36 + 37 _ 14 _ 15 _ 16 _ 17}\)

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

\(=10+10+10+10\)

\(=40\)

\(\text{( 27 + 514 ) _ ( 486 _ 73 )}\)

\(=27+514-486+73\)

\(=\left(27+73\right)+\left(514-486\right)\)

\(=100+28\)

\(=128\)

chúc bạn học tốt

Bài 1: tính hợp lí:

( -12 ) + ( -13 ) + 36 + ( - 11 )

= [ - 12 + ( - 13 ) + ( - 11 ) ] + 36

= ( - 36 ) + 36

= 0

- 16 + 24 + 16 - 34

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

= 0 + ( - 10 )

= - 10

25 + 37 - 48 - 25 - 37

= ( 25 - 25 ) + ( 37 - 37 ) - 48

= 0 + 0 - 48

= - 48

2575 + 37  - 2576 -  29

= ( 2575 - 2576 ) + ( 37 - 29 )

= - 1 + 8

= 7

34 + 35 + 36 + 37  - 14 - 15 - 16 - 17

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

= 20 + 20 + 20 + 20

= 20 x 4

= 80

Bài 2:  bỏ dấu ngoặc rồi tính:

( 27 + 514 )  -  ( 486  - 73 )

= 27 + 514 - 486 + 73

= ( 27 + 73 ) + ( 514 - 486 )

= 100 + 28

= 128

14 + 4 = 18     29 - 5 = 24

18 + 1 = 19     26 - 2 = 24

17 + 2 = 19     10 - 5 = 5

5 + 5 = 10     10 - 2 = 8

38 - 2 = 36     42 + 0 = 42

34 - 4 = 30     49 - 8 = 41

=8

=19

=19

=24

=24

=5

=10

=36

=30

=8

=42

=41 okk

a) 2575+37-2576-29=(2575+2576)-29+37=-1-29+37=-30+37=7

b)34+35+36+37-14-15-16-17=(34-14)+(35-15)+(36-16)+(37-17)=20+20+20+20=80

X

a,2575+37-2576-29=37+[(2575-2576)-29]=37+(-30)=7

b,34+35+36+37-14-15-16-17=(34-14)+(35-15)+(36-16)+(37-17)=20+20+20+20=80