a, [387.2+757].2+10²

⁼[774+757].2+100

=1531.2+100

=3062+100=3162

b, 15+2.(144:12-2.3)

=15+2.(12-6)

=15+2.6=15+12=27

=-45*312-312+312*(-54)

=312(-45-1-54)

=-31200

`#040911`

`a)`

\(37 \times 7 - 17 \times 11 + 13 \times 37 + 17 \times 21\)

`= 37 \times (7 + 13) + 17 \times (21 - 11)`

`= 37 \times 20 + 17 \times 10`

`= 10 \times (37 \times 2 + 17)`

`= 10 \times 91`

`= 910`

`b)`

\(5^5 \times 5^2 \div 5^4 - 2^8 \div 2^4\)

`=`\(5^{5+2-4}-2^{8-4}\)

`= 5^3 - 2^4`

`= 125 - 16`

`= 109`

`c)`

\(3^{11}\times12+3^{12}\times5-3^{14}\)

`=`\(3^{11}\times\left(12+3\times5-3^3\right)\)

`=`\(3^{11}\times\left(12+15-27\right)\)

`=`\(3^{11}\times0=0\)

a) = 259 - 187 + 481 + 357

= 910

b) = 5⁷ : 5⁴ - 2⁴

= 5³ - 2⁴ 

= 125 - 16

= 109

Bài 2:

a, 37 x 7 - 17 x 11 + 13 x 37 + 17 x 21

= ( 37 x 7 + 13 x 37) + ( 17 x 21 - 17 x 11)

= 37 x ( 7 + 13) + 17 x ( 21 - 11)

= 37 x 20 + 17 x 10

= 740 + 170

= 910 

b, 5⁵ x 5² : 5⁴ - 2⁸ : 2⁴

= 5⁷: 5⁴ - 2⁴

= 5³ - 16

= 125 - 16

= 109

c, 3¹¹ x 12 + 3¹² x 5 - 3¹⁴

  3¹¹ x ( 12 + 3 x 5 - 13³)

= 3¹¹ x ( 12 + 15 - 3³)

= 3¹¹ x ( 27 - 27)

 = 3¹¹ x 0

= 0 

( - 45 ) . 312 - 312 - ( - 54 ) . ( - 312 )

= 312 . ( - 45 - 54 - 1 )

= 312 . ( - 100 )

= - 31 200

Bài 2: Tính bằng cách thuận tiện nhất

\(\text{a. 1255 + 436 + 145}\)

\(=\left(1255+145\right)+436\)

\(=1400+436\)

\(=1836\)

\(\text{b. 142 x 12 + 142 x 18}\)

\(=142\times\left(12+18\right)\)

\(=142\times30\)

\(=4260\)

\(\text{c. 4 x 18 x 25}\)

\(=\left(25\times4\right)\times18\)

\(=100\times18\)

\(=1800\)

Bài 2:

a: \(=1400+436=1836\)

b: =142(12+18)

=142*30

=4260

c: \(=100\cdot18=1800\)

Bài 3:

a: \(41m^219dm^2>409dm^2\)

b: \(90000cm^2< 90m^2\)

c: \(30m^26dm^2< 3060dm^2\)

d: \(8012cm^2>8dm^212cm^2\)

e: \(5dm^29cm^2=509cm^2\)

f: \(3940dm^2=39m^240dm^2\)

g: \(300m^26dm^2>3006dm^2\)

h: \(2009cm^2< 21dm^2\)

c) 3⁴ - 5.42

= 81 - 210

= -129

d) 120 : {54 - [50 : 2 - (3² - 2.4)]}

= 120 : {54 - [25 - (9 - 8)]}

= 120 : [54 - (25 - 1)]

= 120 : (54 - 24)

= 120 : 30

= 4

1) (-10)-|5-x|=(-12)

|5-x|=(-10)-(-12)

|5-x|=2

\(\Rightarrow\left[{}\begin{matrix}5-x=2\\5-x=\left(-2\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=3\\x=7\end{matrix}\right.\)

Vậy:............

a: \(4\cdot3^3-75:5^2\)

\(=4\cdot27-\dfrac{75}{25}\)

=108-3

=105

b: \(7\cdot2^4-16\cdot3\)

\(=16\cdot7-16\cdot3\)

=16(7-3)

=16*4=64

c: \(2^3\cdot17-2^3\cdot14\)

\(=8\cdot17-8\cdot14\)

=8(17-14)

=8*3

=24

d: \(45+\dfrac{54}{3^2}\)

\(=45+\dfrac{54}{9}\)

=45+6

=51

e: \(17\cdot85+15\cdot17-120\)

\(=17\left(85+15\right)-120\)

=1700-120

=1580

f: \(\dfrac{3^{24}}{3^{21}}+2^2\cdot2^3\)
 

\(=3^3+2^5\)

=27+32

=59

g: \(92+4^3:8\)

=92+64/8

=92+8

=100

h: \(5\cdot2^3+7^{11}:7^9-1^{2023}\)

\(=5\cdot8+49-1\)

=40+48

=88